• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.577-577
• /
• 2016

기후변화는 전 지구적 현상으로 이로 인한 홍수피해는 심화되고 있다. 기후변화 정부간 협의체 5차 보고서(IPCC, 2014)에 의하면 1980년대 이전 세계 평균 홍수피해액은 70억 달러 수준이었으나 2011년에는 240억 달러로 크게 증가한 것으로 나타났다. 2013년 필리핀에 태풍 '하이옌' 내습으로 인해 6,200여명이 사망하고, 2천여명이 실종되는 피해가 발생하였다. 국내의 경우 2014년 8월 경남 부산지역에는 시간당 130mm가 넘는 국지성 호우에 따라 차량 4,000여대가 침수, 5명 사망 등 약 125억원의 재산피해가 발생한 바 있다. 국회예산정책처(2012)와 소방방재청(2014)에 따르면, 자연재해 중 집중호우 및 태풍에 의한 호우피해가 85%를 차지하였으며, 전국 하천 피해액의 98.7%가 지방 및 소하천에서 발생하고 있다. 이에 따라 중소하천과 같이 소외된 지역의 물복지 향상을 위해서는 홍수재해 상황에 대하여 선제적 효과적 대응을 위한 과학적 체계적인 홍수통합관리 체계의 구축이 요구되고 있다. 특히 홍수관련 유관기관 자료를 연계한 실시간 상 하류 수문상황 모니터링, 홍수분석 및 하천수위별 대응기준 수립, 배수펌프장 등 수리시설원격 제어 등을 포함하는 홍수 통합관리체계 구축과 같은 비구조적 대책의 수립이 제방정비, 저류조 등 구조적 대책과 병행하여 반드시 추진되어야 한다. 이에 K-water는 ICT기반의 물관리기술력과 경험을 활용하여, 인력 기술력 예산 부족 등 열악한 재난관리 여건으로 어려움을 겪고 있는 지자체와 협업을 통해 홍수통합관리체계 구축을 지원하고 있다. 홍수통합관리체계 구축은 지자체 상 하류의 다양한 재난정보를 수집 통합하고, 수집된 정보를 활용한 홍수분석 및 홍수 대응기준 수립을 통해 예방적 재난대응 체계를 마련하는 것으로, K-water는 지난 2010년 남원시를 시작으로 무주군, 군산시, 진안군 등 21개 지자체의 홍수재해 통합관리체계 구축을 지원하고 있다. 특히 남원시의 경우 본 사업을 통한 시스템 구축후 홍수피해액이 50% 감소한 것으로 확인되는 등 재난관련 골든타임을 확보하고 홍수피해 최소화를 위한 홍수재해 통합관리 체계 구축은 이제 선택이 아닌 필수라 할 수 있다. K-water는 물관리 전문 공기업으로써의 역할을 다하고, 예방 중심의 재난관리 체계 마련을 위해 '지자체 맞춤형 홍수통합관리체계' 구축 지원을 지속적으로 확대해나갈 예정이다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.294-294
• /
• 2019

The system for predicting flood of river at Flood Control Office is made up of a rainfall-runoff model and FLDWAV model. This system is mainly operating to predict the excess of the flood watch or warning level at flood forecast points. As the demand for information of the management and operation of riverside, which is being used as a waterfront area such as parks, camping sites, and bike paths, high-level forecasts of watch and warning at certain points are required as well as production of lowland flood forecast information that is used as a waterfront within the river. In this study, a technology to produce flood forecast information in lowland areas of the river used as a waterfront was developed. Based on the results of the 1D hydraulic analysis, a model for performing spatial operations based on high resolution grid was constructed. A model was constructed for Andong district, and the inundation conditions and level were analyzed through a virtual outflow scenarios of Andong and Imha Dam.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.2
• /
• pp.404-411
• /
• 2019

In this study, the HEC-HMS was applied to determine rainfall-runoff processes for the Gokgyuchun basin. Several sub-basins have large-scale reservoirs for agricultural needs and they store large amounts of initial runoff. Three infiltration methods were implemented to reflect the effect of initial loss by reservoirs: 'SCS-CN'(Scheme I), 'SCS-CN' with simple surface method(Scheme II), and 'Initial and Constant rate'(Scheme III). Modeling processes include incorporating three different methods for loss due to infiltration, Clark's UH model for transformation, exponential recession model for baseflow, and Muskingum model for channel routing. The parameters were calibrated using an optimization technique with trial and error method. Performance measures, such as NSE, RAR, and PBIAS, were adopted to aid in the calibration processes. The model performance for those methods was evaluated at Gangcheong station, which is the outlet of study site. Good accuracy in predicting runoff volume and peak flow, and peak time was obtained using the Scheme II and III, considering the initial loss, whereas Scheme I showed low reliability for storms. Scheme III did not show good matches between observed and simulated values for storms with multi peaks. Conclusively, Scheme II provided better results for both single and multi-peak storms. The results of this study can provide a useful tool for decision makers to determine master plans for regional flood control management.

• Journal of Korean Society of Disaster and Security
• /
• v.14 no.1
• /
• pp.61-72
• /
• 2021

There is an increasing need for water supply plan using sustainable groundwater to resolve water shortage problem caused by drought due to climate change and artificial aquifer recharge has recently emerged as an alternative. This study deals with recharge potential assessment for artificial recharge system and quantitative assessment for securing stable water and efficient agricultural water supply adapt to drought finding optimal operating condition by numerical modeling to reflect recharge scenarios considering climate condition, target water intake, injection rate, and injection duration. In order to assess recharge potential of injection well, numerical simulation was performed to predict groundwater level changes in injection and observation well respect to injection scenarios (Case 1~4) for a given total injection rate (10,000 m³). The results indicate that groundwater levels for each case are maintained for 25~42 days and optimal injection rate is 50 m³/day for Case 3 resulted in groundwater level rise less than 1 m below surface. The results also show that influential area of groundwater level rise due to injection was estimated at 113.5 m and groundwater storage and elapsed time were respectively increased by 6 times and 4 times after installation of low permeable barrier. The proposed assessment method can be contributed to sustainable agricultural water supply and stable water security for drought adaptation.

• Journal of the Korean Institute of Gas
• /
• v.27 no.2
• /
• pp.71-78
• /
• 2023

In general, electric submersible pumps (ESPs), which have an average life of 1.0 to 1.5 years, experience a decrease in performance and a reduction in life of the pump depending on oil and gas reservoir characteristics and operating conditions in wells. As the result, the failure of ESP causes high well workover costs due to retrieval and installation, and additional costs due to shut down. In this study, a flow loop system was designed and established to predict the life of ESP in long­term operation of oil and gas wells, and the life cycle data of ESP from the time of installation to the time of failure was acquired and analyzed. Among the data acquired from the system, flow rate, inlet and outlet temperature and pressure, and the data of the vibrator installed on the outside of ESP were analyzed, and then the performance status according to long-term operation was classified into five stages: normal, advice I, advice II, maintenance, and failed. Through the experiments, it was found that there was a difference in the data trend by stage during the long­term operation of the ESP, and then the condition of the ESP was diagnosed and the failure of the pump was predicted according to the operating time. The results derived from this study can be used to develop a failure prediction program and data analysis algorithm for monitoring the condition of ESPs operated in oil and gas wells.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.441-441
• /
• 2021

우리나라의 홍수조절용댐은 총 5개소로 영산강유역에 두 개소와 한강유역에 세 개소가 있다. 한강유역에 있는 세 개소의 홍수조절지용댐은 한강상류의 북한지역에서 발생하는 집중호우에 대비하기 위한 댐으로, 임진강 하류지역의 수해방지를 위한 한탄강댐과 군남홍수조절지(군남댐)가 있으며 북한강 하류와 수도권의 홍수예방을 위한 평화의 댐이 있다. 영산강유역에 있는 두 개소의 홍수조절지는 2006년에 수립한 영산강치수종합대책에서 계획이 수립된 시설로 2011년 4대강 사업의 일환으로 설치하여 K-water에서 운영 중에 있다. 4대강 사업 이전의 영산강유역은 홍수량을 조절할 수 있는 홍수조절용량이 전무했던 실정으로 하도에서 홍수량의 전량을 수용해야했던 홍수에 매우 취약한 하천이었다. 그러나 4대강 사업을 통하여 영산강유역의 4대호를 비롯한 농업용댐의 숭상을 통한 홍수조절용량의 확보와 더불어 나주천변저류지와 담양홍수조절지, 화순홍수조절지를 설치하여 홍수로부터 상대적으로 안전한 하천으로 변모할 수 있었다. 그러나 영산강유역의 다른 하나의 과제는 여전히 남아있다. 우리나라의 하천 중에서 가장 수질이 악화되어 있는 하천이라는 불명예이다. 홍수조절지는 1년 중 3개월에 해당하는 홍수기에 사용할 수 있는 시설로 1년 중 9개월에 해당하는 비홍수기에는 홍수조절지의 효율적인 공간활용을 위하여 주민지원사업 등 다각도로 고민하여 사용하고 있으나 하천 외적인 문제를 수용하는 범주에 머무르고 있다. 하천이 가지고 있는 문제점을 다소라도 해소할 수 있는 목적으로 사용될 수 있다면 하천 외적인 문제를 수용하는 것 보다 하천 내적인 문제를 해소하는 목적으로 사용하는 것이 보다 바람직할 것으로 판단된다. 이를 위하여 영산강의 내적인 가장 큰 문제점은 수질악화로 인한 수질개선이라 할 수 있다. 따라서 홍수기로 한정되어 사용하는 홍수조절지를 해당하천의 내적인 문제를 다소라도 해소할 수 있는 공간으로 비홍수기에 기여할 수만 있다면 비홍수기의 활용목적을 확대하여 다목적조절지로의 변모가 필요하다고 판단한다. 따라서 본 연구에서는 영산강유역에 있는 담양홍수조절지와 화순홍수조절지의 두 개소 홍수조절지를 활용하여 영산강 수질개선에 기여할 수 있는 정도를 파악하였다. 비홍수기에 유출량의 일부를 조절지에 담수해 두었다가 수질개선 목적의 희석수로 방류하는 시나리오를 마련하여 시나리오별로 영산강의 수질개선효과를 분석하여 제시하였다. 수질개선효과를 분석하기 위하여 EFDC모델을 구축하고 모델 수행을 위한 시나리오는 조절지의 담수율과 방류량 그리고 조절지의 관리수질조건 등을 이용하여 작성하고 수질예측 결과에 따라 TOC, CHl-a, T-P 수질항목을 대상으로 수질개선효과를 분석하여 제시하였다.

• Tunnel and Underground Space
• /
• v.33 no.5
• /
• pp.348-372
• /
• 2023

In relation to the high-level radioactive waste disposal project in deep fractured rock aquifer environments, it is essential to evaluate hydrogeological characteristics for evaluating the suitability of the site and operational stability. Such subsurface hydrogeological data is obtained through in-situ tests using boreholes excavated at the target site. The accuracy and reliability of the investigation results are directly related to the selection of appropriate test methods, the performance of the investigation system, standardization of the investigation procedure. In this report, we introduce the detailed procedures for the representative test method, the constant pressure injection test (CPIT), which is used to determine the key hydrogeological parameters of the subsurface fractured rock aquifer, namely hydraulic conductivity and storativity. This report further refines the standard test method suggested by the KSRM in 2022 and includes practical field application case conducted in volcanic rock aquifers where this investigation procedure has been applied.

• The korean journal of orthodontics
• /
• v.36 no.4
• /
• pp.284-294
• /
• 2006

Objective: Activating mutations in the fibroblast growth factor receptor-2 (FGFR2) have been shown to cause syndromic craniosynostosis such as Apert and Crouzon syndromes. The purpose of this pilot study was to investigate the resultant phenotypes induced by the two distinctive bone-targeted gene constructs of FGFR2, Pro253Arg and Cys278Phe, corresponding to human Apert and Crouzon syndromes respectively. Methods: Wild type and a transgenic mouse model with normal FGFR2 were used as controls to examine the validity of the microinjection. Micro-CT and morphometric analysis on the skull revealed the following results. Results: Both Apert and Crouzon mutants of FGFR2 induced fusion of calvarial sutures and anteroposteriorly constricted facial dimension, with anterior crossbite present only in Apert mice. Apert mice differed from Crouzon mice and transgenic mice with normal FGFR2 in the anterior cranial base flexure and calvarial flexure angle which implies a possible difference in the pathogenesis of the two mutations. In contrast, the transgenic mice with normal FGFR2 displayed normal craniofacial phenotype. Conclusion: Apert and Crouzon mutations appear to lead to genotype-specific phenotypes, possibly causing the distinctive sites and sequence of synostosis in the calvaria and cranial base. The exact function of the altered FGFR2 at each suture needs further investigation.

• Journal of the Korean Institute of Gas
• /
• v.22 no.5
• /
• pp.53-61
• /
• 2018

Low-salinity water based polymerflooding (LSPF) is one of promising enhanced oil recovery (EOR) method that has the synergetic effect of combining polymer injection method and low-salinity water injection method. In order to maximize EOR efficiency, it is essential to design low-salinity water appropriately considering the properties of polymer. In this aspect, the main purpose of this study is to investigate the effect of pH and $SO_4{^{2-}}$ ion which one of PDI (Potential Determining Ion) on oil production when applying LSPF to carbonate oil reservoir. First, the stability and adsorption of polymer molecule were analyzed in different pH of injection water and $SO_4{^{2-}}$ concentration in injection water. As a result, regardless of pH and $SO_4{^{2-}}$ concentration, when $SO_4{^{2-}}$ ion was contained in injection water, the stability of polymer solution was obtained. However, from the result of polymer retention analysis, in neutral state of injection water, since $SO_4{^{2-}}$ interfered the adsorption of polymer, the adsorption thickness of polymer was thinner as $SO_4{^{2-}}$ concentration was higher. On the other hand, when injection water was acidic as pH 4, the amount of polymer adsorption increased with the injection of polymer solution, so the mobility of polymer solution was greatly lowered. From the results of wettability alteration due to low-salinity water effect, in the case of neutral injection water injected, as $SO_4{^{2-}}$ concentration was increased, more oil which attached on rock surface was detached, altering wettability from oil-wet to water-wet. On the other hand, in acidic condition, due to complex effect of rock dissolution and polymer adsorption, wettability of the entire core system was less altered relatively to neutral condition. Therefore, it was evaluated that better EOR efficiency was obtained when injecting low-salinity water based polymer solution containing high concentration of $SO_4{^{2-}}$ with neutral condition, enhancing the oil production up to 12.3% compared to low-salinity water injection method.

• Journal of Korea Water Resources Association
• /
• v.40 no.10
• /
• pp.769-781
• /
• 2007

Factor analysis has been usually employed in reducing quantity of data and summarizing information on a system or phenomenon. In this analysis methodology, variables are grouped into several factors by consideration of statistic characteristics, and the results are used for dropping variables which have lower weight than others. In this study, factor analysis was applied for extracting primary factors influencing multi-dam system operation in the Han River basin, where there are two multi-purpose dams such as Soyanggang Dam and Chungju Dam, and water has been supplied by integrating two dams in water use season. In order to fulfill factor analysis, first the variables related to two dams operation were gathered and divided into five groups (Soyanggang Dam: inflow, hydropower product, storage management, storage, and operation results of the past; Chungju Dam: inflow, hydropower product, water demand, storage, and operation results of the past). And then, considering statistic properties, in the gathered variables, some variables were chosen and grouped into five factors; hydrological condition, dam operation of the past, dam operation at normal season, water demand, and downstream dam operation. In order to check the appropriateness and applicability of factors, a multiple regression equation was newly constructed using factors as description variables, and those factors were compared with terms of objective function used in operation water resources optimally in a river basin. Reviewing the results through two check processes, it was revealed that the suggested approach provided satisfactory results. And, it was expected for extracted primary factors to be useful for making dam operation schedule considering the future situation and previous results.