• Journal of Korea Water Resources Association
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• v.52 no.10
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• pp.729-742
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• 2019

Natural disasters such as floods has been increased in many parts of the world, also Korea is no exception. The biggest part of natural damage in South Korea was caused by the flooding during the rainy season in every summer. The existing flood vulnerability analysis cannot explain the reality because of the repeated changes in topography. Therefore, it is necessary to calculate a new flood vulnerability index in accordance with the changed terrain and socio-economic environment. The priority of the investment for the flood prevention and mitigation has to be determined using the new flood vulnerability index. Total 25 urban districts in Seoul were selected as the study area. Flood vulnerability factors were developed using Pressure-State-Response (PSR) structures. The Pressure Index (PI) includes nine factors such as population density and number of vehicles, and so on. Four factors such as damage of public facilities, etc. for the Status Index (SI) were selected. Finally, seven factors for Response Index (RI) were selected such as the number of evacuation facilities and financial independence, etc. The weights of factors were calculated using AHP method and Fuzzy AHP to implement the uncertainties in the decision making process. As a result, PI and RI were changed, but the ranks in PI and RI were not be changed significantly. However, SI were changed significanlty in terms of the weight method. Flood vulnerability index using Fuzzy AHP shows less vulnerability index in Southern part of Han river. This would be the reason that cost of flood mitigation, number of government workers and Financial self-reliance are high.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.77-77
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• 2018

한국 건설기술연구원의 하천실증연구센터는 기존에 불가능했던 준 실규모 하천실험, 생태실험, 치수분야 대형 모형실험 및 하천관련 기준수립을 위한 치수분야 수요와 하천 구조물의 품질성능평가 등을 목적으로 설립된 대규모 하천실증연구센터이다. 안동 하천실증연구센터는 총면적 $193,051m^2$의 부지에 하천의 일반적인 형상을 갖고 있는 완경사, 급경사, 만곡수로가 있으며, 수리량 측정 실험을 위한 초음파 유속계, 프로펠러 유속계, 전자식 유속계 등의 유속 측정 장비를 보유하고 있고, Total Station, Lidar, RTK-GPS 등 지형 측량에 사용할 수 있는 장비들도 보유하고 있어, 하천관련 실험을 수행하기에 충분한 여건을 보유하고 있다. 하천실증연구센터는 2013년부터 내 외부활용에서 활용할 수 있도록 지원을 수행하였으며, 총 118건의 하천 수리 및 생태분야, 지반분야 등 다양한 토목분야의 연구자들이 하천실증연구센터를 방문하여 실험을 수행하였고, 국내 기관 및 대학뿐만 아니라 미국의 Iowa 대학, Idaho 대학, USGS, 네덜란드 Deltares, 프랑스 Irstea 등 외국의 대학 및 기관에서도 방문하여 실험 및 공동연구를 수행하였다. 안동 하천실증연구센터의 활용 범위와 활용 건수가 지속적으로 증가함에 따라 자체적인 검토 및 외부의 의견에 따라 센터의 실험시설에 대한 개선이 필요한 사항이 발생하게 되었다. 하천실증연구센터의 수로는 기존의 지반위에 성토를 하여 인공적으로 건설하였기 때문에 일반적인 실내의 실험수로와는 다르게 하상에서의 침투가 발생하며, 이에 따라 하류방향으로 흐름이 진행될수록 유량의 변동이 발생하게 된다. 이에 따라 침투로 인해 발생하는 유량의 변동이 하도 유량 공급의 안정화에 미치는 영향에 대한 신뢰성 검증의 필요성이 필요하다고 판단되어 펌프에서의 유량 공급 및 하도내에서의 유량 안정화에 대한 검증 실험을 수행하고자 한다. 유량 공급에 대한 검증 실험은 크게 두 단계로 구성하였다. 첫 번째 단계는 펌프의 유량 공급에 대한 검증실험을 수행하고, 두 번째 단계에서는 동일한 조건내에서 하류의 지하수 수심, 공급수조의 수심, 하도내의 수심과 ADV 및 ADCP로 측정된 유량과의 관계를 통해 하도내의 유량이 얼마나 일정하게 공급되고, 하류방향으로 갈수록 유량 손실의 경향에 대한 실험을 계획하였으며, 전체적인 실험은 장기적으로 각 수로에 대하여 수행하는 것을 목표로 하였으며, 본 실험단계에서는 완경사 수로를 대상으로 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.416-416
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• 2015

기후변화는 미래 강수량 변동을 야기하여 하천유량 관리에 큰 영향을 미칠 것으로 예상하고 있다. 이에 본 연구에서는 기후변화에 따른 중장기 하천유량 관리를 위하여 금호강 유역을 대상으로 SWAT 모형을 이용하여 중장기 하천유량을 예측하였다. 임하댐 상류지역의 2008~2012년 유량자료에 대하여 보정 완료된 SWAT 모형을 기반으로, 지역기후모형(RCM)인 HadGEM3-RA모형을 활용한 IPCC 제5차 보고서 RCP 4.5, RCP 8.5 시나리오를 적용하였다. 금호강 표준유역별 기후변화에 의한 영향을 모의하기 위하여 편이보정(Bias Correction)방법을 적용하였으며, 금호강 유역 내 과거 30년(1975~2005년, Baseline) 기상자료와 비교하여 통계적인 유사성을 가지도록 보정을 실시하였다. 기후변화 시나리오 적용결과는 S1(2011~2040년), S2(2041~2070년), S3(2071~2099년)으로 분할하여 월별, 계절별, 연도별 미래 강수량과 기온을 분석하였다. 분석 결과, RCP 4.5 시나리오의 경우 봄철(3~5월)의 강수량은 기준년도에 비해 약 57%가 증가하였으나, 가을철(6~8월)에는 7.9% 감소하였으며, 첨두 강수시기는 8~9월에서 6~7월로 이동하였다. 평균기온은 각 구분 시기별 $0.2^{\circ}C$, $1.1^{\circ}C$, $1.8^{\circ}C$ 정도 상승할 것으로 예측되었다. RCP 8.5 시나리오에서는 기준년도 대비 강우량은 봄철에 61% 증가, 가을철에는 14.9% 감소하는 것으로 모의되었다. 평균기온은 약 $0.4^{\circ}C$, $2.1^{\circ}C$, $4.2^{\circ}C$ 정도 상승하는 것으로 나타났다. 기후변화에 따른 유출량 결과 비교는 2001~2010년을 기준으로 하였으며, RCP 4.5 시나리오에서는 S1, S2, S3 시기별 각각 -10.9%, -7%, -3.6% 감소하였으며, RCP 8.5 시나리오에서는 약 -12.3%, 4.9%, -1.2% 변동하는 것으로 나타냈다. 금호강 유역 전반에 걸쳐 유출량이 감소하는 추세를 보였으며, 특히 본류에 비해 지류유역의 건천화가 심해지는 양상을 보였다. 또한 현재에 비해 여름철 유출패턴 시기가 앞당겨져 봄철 유량이 증가하고 겨울철에 감소하는 경향을 보이고 있다. 기후변화로 인한 수문패턴의 변화로 현재 하천유량관리의 변화가 필요할 것으로 판단되며, 향후 본 연구결과를 바탕으로 물수지 분석을 추가하여 유지유량 만족을 위한 해당유역의 이수기 유량관리 방안 연구를 수행할 예정이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.487-487
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• 2018

본 연구에서는 2017년 5월부터 12월까지 주단위로 낙동강 수계 5개 보 구간(칠곡보~창녕함안보)에서 본류와 유입지천의 유기물(BOD, $COD_{Mn}$, TOC) 분석 및 상관관계 조사하였으며, 강정고령보~창녕함안보의 대표지점에 대해서는 용존유기물(DOC)의 분해특성을 조사하였다. 본류의 유기물 농도는 BOD $2.7mgO_2/L$($2.3{\sim}3.1mgO_2/L$), $COD_{Mn}$ $5.6mgO_2/L$($5.0{\sim}6.2mgO_2/L$), TOC 4.7 mgC/L($4.2{\sim}5.2mgO_2/L$), 유입지천은 BOD $3.4mgO_2/L$($1.1{\sim}5.6mgO_2/L$), $COD_{Mn}$ $7.1mgO_2/L$($2.5{\sim}10.9mgO_2/L$), TOC $5.7mgO_2/L$(2.3~8.7 mgC/L)로 각각 나타났다. 유기물간 상관성 분석결과 본류의 BOD와 COD, TOC 상관계수(r)은 각각 0.97, 0.98, COD와 TOC는 0.91, 유입지천의 BOD와 COD, TOC는 각각 0.81, 076, COD와 TOC는 0.99로 나타났다. 본류 구간에서 탄소로 환산된 BOD-C/TOC 산화율은 21.5%(20.4~22.5%), COD-C/TOC 45.7%(44.3~48.0%), 유입지천의 BOD-C/TOC 산화율은 23.6%(13.1~31.0%), COD-C/TOC 48.0%(41.3~53.3%)로 각각 나타났다. 강정고령보~창녕함안보 대표지점의 DOC 분해특성은 DOC 중 R-DOC가 86.9%(74.5~94.3%), L-DOC 13.0%(5.7~25.5%)로 나타났다. L-DOC의 분해속도(k)는 0.21 /day(0.11~0.38 /day)로 계산되었으며, 보별 평균 분해속도는 합천창녕보(0.25 /day) > 강정고령보(0.22 /day) > 창녕함안보(0.21 /day) > 달성보(0.18 /day)순으로 나타났다. 유기물 농도는 본류에서는 하류로 갈수록 증가하는 경향을 보였으며, 유입지천은 지점별로 다양하게 나타났다. 유기물간 상관성은 유입지천보다 본류구간이 상관계수가 높게 나타났다. TOC에 대한 BOD와 $COD_{Mn}$산화율은 본류구간 보다 유입지천에서 큰 변동을 보였으며, 실제 유기물 총량 대비 BOD와 $COD_{Mn}$은 각각 77.0%, 52.7% 낮게 나타났다. DOC 중 난분해성 유기물이 대부분을 차지하였으며, 타 보 대비 달성보 내에 난분해성 유기물이 높은 것으로 나타났다.

• Korean Journal of Plant Taxonomy
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• v.46 no.4
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• pp.413-419
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• 2016

Two unrecorded naturalized species, Stachys agraria Schltdl. & Cham. and Dracocephalum moldavica L (Lamiaceae), are newly reported in Korea. Stachys agraria and D. moldavica were found at Seogwipo-si on Jeju-do and at ChunChen-si in Gangwondo in Korea, respectively. Stachys agraria is distinguished from other related Korean taxa by corolla of 2.4-5.2 mm long with six to twelve flowers in the node. Its local name is "Ae-gi-seok-jam-pul" based on shorter than longer corollar. Dracocephalum moldavica was distinguishable from other Dracocephalum in Korea by the following combination of characters, oblong to ovate-triangular ($1.7-2.4cm{\times}0.8-1.2cm$) leaves and rough crenate at the margin. This taxon is referred to as 'Hyang-yong-meo-ri' in Korean based on its fragrance. We provide a description, illustrations, photographs, and a key of related taxa in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.2
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• pp.66-71
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• 2005

Soil loss into stream and river by runoff shall be considered for non-point source pollution management as national land conservation. The purpose of this study was to develop the mathematical equation to predict soil loss from inclined uplands of maize cultivation due to the runoff by rainfall which mainly converges on July and August. Soil loss was concentrated on May because of low canopy over an entire field in 2002 and on June and July because of heavy rainfall in 2003. By regression analysis the relation between runoff and soil loss can be represented by a linear equation of y =1.5291x - 3.4933, where y is runoff ($Mg\;ha^{-1}$) and x is soil loss ($kg\;ha^{-1}$). The determination coefficient of this equation was 0.839 (P<0.001). Therefore, the mathematical equation derived from the practical experiment at the inclined upland can be applicable to predict soil loss accompanied by runoff due to periodic rainfall converging on short periods within a couple of months.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.599-615
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• 2022

In order to excavate underground tunnel most safely such as Han river, the slurry shield TBM method is applied to cope with face of high water pressure for many metro projects. In downtown subway project most of excavated soil is discharged externally whereas in road construction excavated soil is used as filling materials so it becomes important factor for success of the project. After excavated soil, weathered rock and soft rock are discharged with bentonite through discharge pipe to slurry treatment plant then those soils are separated in separation plant according to those size. Fine grained soil has been discarded together with filter cake but it is not toxic and can be mixed with coarse aggregate in proper ratio so this study is performed to find use of qualified filling material to meet quality standard. Therefore, in this study, legal standards and quality standards for the utilization of excavated soil of the slurry shield TBM method were examined and test was conducted to derive recycling way for filter cake and aggregate. And a plan for using it as a filling material for road construction was derived. Because bentonite is a clay composed of montmorillonite, and the excavated soil in the tunnel is also non-toxic, disposal of this material can waste social cost so it is expected to be helpful in the underground space development project that carries out the TBM project by recycling it as a valuable resource.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.637-658
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• 2022

TBM tunnel is simple with the iterative process of excavating the ground, building a segment ring-build, and backfilling. Drill & Blast, a conventional tunnel construction method, is more complicated than the TBM tunnel and has some restrictions because it repeats the inspection, drilling, charging, blasting, ventilation, muck treatment, and installation of support materials. However, the preparation work for excavation requires time and cost based on a very detailed plan compared to Drill & Blasting, which reinforces the ground and forms a tunnel after the formation of tunnel portal. This is because the TBM equipment for excavating the target ground determines the success or failure of the construction. If the TBM, an expensive order-made equipment, is incorrectly configured at the assembly stage, it becomes difficult to excavate from the initial stage as well as the main excavation stage. When the assembled shield TBM equipment is dismantled again, and a situation of re-assembly occurs, it is difficult throughout the construction period due to economic loss as well as time. Therefore, in this study, the layout and plan of the site and the assembly process for each major part of the TBM equipment were reviewed for the assembly of slurry shield TBM to construct the largest diameter road tunnel in domestic passing through the Han River and minimized interference with other processes and the efficiency of cutter head assembly and transport were analyzed and improved to suit the site conditions.

• Journal of Korea Water Resources Association
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• v.54 no.12
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• pp.1329-1338
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• 2021

Rain radar provides high spatio-temporal radar rainfall that can be used as input data to short-term precipitation forecasting models. Korea Institute of Civil Engineering and Building Technology (KICT) has developed a flash flood forecasting system that is providing flash flood forecasting based on short-term rainfall forecasts estimated by the radar rainfall. Accuracy of the radar rainfall as well as the short-term rainfall forecasts, however, can deteriorate when radar polarimetric variables have error. In this study, we develope real-time program that can correct the error inherent in the radar polarimetric variables. First, effect according to the correction of the error was verified using 363 rainfall events on non real-time. The accuracy (1-NE) of the radar rainfall was approximately 70% and correlation coefficient was higher than 0.8 after correcting the error on non real-time. The accuracy (1-NE) using the real-time program was also approximately 70% after correcting the error.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.370-382
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• 2018

The purpose of this study is to quantitatively and effectively evaluate the factors affecting flood damage by watershed. National Water Resource Plan(MOCT, 2001) has been developed Potential Flood Damage(PFD) which indicates flood vulnerability. But, it is only a simple grouping and it does not provide guidelines for flood control planning based on detailed evaluation of sub-components. In this study, we used PFD in the Han River basin according to the method applied in the National Water Resource Plan (existing method) and improvement based on actual flood hazard area and data. As an application method, after analyzing by yearly change(2009~2014), we compared and analyzed the tendency of the sub - components that constitute the potential and risk rather than the current grouping. As the result, it was possible to accurately evaluate the existing and improved methods, and it was possible to derive the vulnerability rankings, but the existing methods have different results from the actual watershed tendency. Therefore, the PFD of the improvement method that correctly reflects past history and watershed characteristics is more appropriate for the evaluation of flood vulnerability in the watershed. In addition, it is reasonable to establish a flood control plan referring to this and prevent flood damage in advance.