• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.1
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• pp.29-39
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• 2018

In this study, the applicabilities of flood risk indices using FVI from IPCC, PSR method from OECD, and DPSIR method from EEA, were analyzed. Normalized values of daily maximum rainfall, hourly maximum rainfall, ten minute maximum rainfall, annual precipitation, total days of heavy rainfall (more than 80mm/day), density of population, density of asset, DEM, road statistics, river maintenance ratio, reservoir capacity, supply ratio of water supply and sewerage, and pumping capacity were constructed from 2000 to 2015 for nationwide 113 watersheds, to estimate flood risk indices. The estimated indices were compared to 4 different types of flood damage such as the number of casualties, damage area, the amount of flood damage, and flood frequency. The relationships between flood indices and different flood damage types demonstrated that the flood index using the PSR method shows better results for the amount of flood damage, the number of casualties and damage area, and the flood index using the DPSIR method shows better results for flood frequency.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.2
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• pp.68-77
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• 2002

We investigated the outbreak, maintenance, and decline of the red tide dominated by C. polykrikoides in the coastal waters off Southern Korea from August to October, 2000, by combining field data and NOAA satellite images. In general, the C. polykrikoides blooms, which have occured annually in Korean coastal waters from 1995 to 1999, initiate between late August and early September around Narodo Island and expand to the whole area of the southern coast. However, initiation and short-term change of the bloom of 2000 were quite different from the pattern observed previously. In mid-August, thermal fronts in sea surface temperature(SST) were formed: 1) between the Tsushima Warm Current Water (TWCW) and the Southern Korean Coastal Waters (SKCW), 2) between the jindo cold water mass and the southwestern coastal waters, and 3) between the upwelled cold waters in the southeast coast and the offshore warm waters. Free-living cells of C. polykrikoides were concentrated in these frontal regions. In late August, the thermal front TWCW-SKCW approached the mouth of Yeosuhae Bay where Seomjin River water and anthropogenic pollutants from the Industrial Complex of Gwangyang Bay are discharged. In the blooms of 2000 initiated in Yeosuhae Bay in late August, the dominant species, C. polykrikoides, co-occured with Alexandrum tamarense, Gymnodinium mikimotoi, Skeletonema coastatum, and Chaetoceros spp. Two typhoons, 'Prapiroon' and 'Saomai' during and the C. polykrikoides bloom probably affected the abundance of this species. After the former typhoon passed the Korean Peninsula, cell growth of C. polykrikoides was maximal, but after the latter typhoon, the C. polykrikoides bloom disappeared (20 September). On 5 October, the blooms dominated by C. polykrikoides broke out within the coastal waters of Jinhae Bay and Hansan-Keoje Bay. NOAA satellite images showed that the isothermal line of 22$^{\circ}C$ extended into Jinhae Bay. In this bloom, C. polykrikoides also occurred simultaneously with Akashiwo sanguinea(=Gym-nodinium sangunium), a common red tide-forming dinoflagellate species in fall and winter in these coastal bays.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.41-58
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• 2003

This study was conducted to investigate bird community and to suggest a proper way how to manage protect bird community in Gap stream. The survey was carried out over four sections by the line transect method and point counts method from September 2001 to August 2002. Natural stream region as Gasuwon Bridge - Mannyeon Bridge are observed birds were 11 orders 29 families 67 species, Artificial stream region as Mannyeon Bridge - Daedeok Bridge are observed birds were 6 orders 10 families 30 species, Daedeok Bridge - Wonchon Bridge are 8 orders 12 families 28 species, Wonchon Bridge - Gap Stream Bridge are 8 orders 18 families 40 species. All the observed birds in artificial stream region are 8 orders 19 families 47 species. Number of species in natural stream region was higher than artificial stream region owe to a various habitat environment such as forest, cultivated land, streamside forest, sandy plain, gravelly field, reedy field etc. and can not add with the interface and the usage of the human. Number of species in artificial stream region was lower than natural stream region owe to a simple habitat environment and the water ecosystem is severed with embankment block and grass plot with the land ecosystem. The furtherance of various habitat environment which considers the ecosystem like the natural stream as the water ecosystem is joined together with the land ecosystem is desired to attract various wildbirds in Gap stream. The design is desired with the maintenance of the stream to consider the stream corridor which plays ecological important role as connect the fragment habitats.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.209-213
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• 2006

청계천이 복원되었다. 서울시에 의하여 지난 2003년 7월부터 시작된 복원공사가 2005년 10월 준공되었다. 원래부터 청계천은 인공의 하천이었다. 조선왕조 520년의 기틀을 다지면서, 도성에 있는 자연하천을 직강화하고 양안에 석축을 쌓아 개천으로 만들었던 것이다. 하천에 인위적인 요소를 더한 것은 전적으로 홍수의 피해를 줄이기 위해서였다. 조선왕조실록에는 태종부터 헌종까지 도성에서 발생한 큰 홍수기록이 10건 소개되어 있다. 특히, 순조 32년(1832)과 헌종 12년(1846)의 피해가 컸었다. 순조 32년 6월부터 7월초까지 비가 오지 않은 날이 없다고 하였으며, 도성내 5부의 민가가 파괴된 것은 3,166호였고 죽은 자는 64명이었다. 헌종 12년 9월에도 큰 피해가 있었는데, 5부에 무너진 민가가 3,900여호나 되었다. 4대문 안의 서울은 북악산과 남산으로부터 가파르게 흐른 물이 고이기 쉬운 저지대를 형성하고 있기 때문에 침수 피해가 자주 발생하였다. 개국 초기에 여러차례의 홍수피해를 당한 후에, 태종의 본격적인 하천정비 사업은 세종 때에 완성되어 오늘날 청계천의 기본 모습을 갖추게 되었다. 임진왜란이후 개천은 상류에서 쓸려내여온 토사가 쌓여 하천으로서의 구실을 다하지 못하였다. 영조 때에는 매립된 토사로 인하여 하천 바닥이 높아졌고, 양안의 도로와 거의 같은 높이가 되었다고도 한다. 이에 영조는 대대적인 준설 사업을 펼쳤고 조선이 폐망할 때까지 주기적으로 준설을 하였다. 준설만을 한 것은 아니었다. 세종은 측우기의 발명과 함께 한강과 개천의 수위를 측정할 수 있도록 수표(水標)를 제작하였고, 역대 왕들은 큰 비가 오면 강우량과 함께 하천의 수위를 점검하였었다. 청계천을 중심으로 자연의 거친 손길에 대응하여 안정된 사회를 만들고자 조선의 왕들과 관리 그리고 백성들은 많은 노력을 기울였다. 본 고에서는 이러한 선조들의 발자취를 따라서 그 흔적들을 소개하고자 한다.없는 토양들이 있었는데 반해 남계통을 비롯한 학곡통, 회곡통, 백산통, 상주통, 석천통, 예산통 등 7개의 토양은 3kPa에서도 약간의 물의 이동이 있었다. 이는 모암이 화강 편마암인 관계로 토양 내에 물의 이동에 영향을 미치는 자갈의 함량이 높았기 때문일 것으로 생각되고 추후의 연구에서는 이 부분에 대한 내용도 검토되어야 할 것이다. 또한, 1kPa에서 물의 이동은 삼각통에서 35.21 cm/day로 이동 속도가 가장 컸으며 그 뒤로 예산통, 화봉통, 학곡통, 백산통 등이 토양에서 빠른 속도로 이동하였다. 가천통이나 석천통 및 우곡통은 1kPa에서의 이동 속도가 아주 느린 토양으로 판단되었다. 또한, 포화되지 않은 상태인 1kPa에서 물의 이동 속도를 VGM 모형에 의해 예측된 값과 측정된 값으로 비교하였을 때 불포화 수리 전도도가 예측되지 않은 토양(석천통, 지곡통, 풍천통)이 존재하여 불포화 수리 전도도 특성평가에 대한 VGM 모형의 적용성에 문제를 보였다. 이는 결과적으로 논이라는 영농형태가 존재하는 우리나라에서 토양의 수리적 특성해석을 위한 VGM 모형의 적용성에 한계가 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다 더욱 긴 분석기간의 주식가격정보에 의하여 최대한

• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.91-99
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• 2012

In this study, it was proposed that extension techniques of 8 day interval recorded stream-flow data which has been produced at the mouth of unit watersheds for TMDLs to daily one. The concept of this method was that the missing data at partial recording station was filled by using the daily data at a nearby, hydrologically similar streamgaging station. First, same day stream-flow was extracted from the daily stream-flow. Then, the extension equation was developed based on the sample data when the same day stream-flow from daily data and the partially recorded stream-flow was deeply related each other. The missing data was interpolated or extrapolated by the equation. Especially the maintenance of variance extension (MOVE) technique was used to derive the equation and was validated. Finally the 8-day interval recorded stream-flow at the mouth of unit watersheds in Han River Basin for TMDLs was extended to continuously daily data by using the method proposed in this study. And the low flow at each unit watershed was evaluated according to the flow-duration curve.

• Journal of Korea Water Resources Association
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• v.56 no.2
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• pp.139-150
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• 2023

Terretial LiDAR surveying is highly useful for maintenance of civil facilities as it can easily detect the temporal deformation of structures or topography. However, for river facilities such as levess, it is difficult to detect the deformation of the topography or structure under vegetations due to the influence of vegetation. Vegetation filters can be divided into color filters and morphological filters. In this study, combined filters with color and morphology are developed to improve the accuracy of vegetation filters. 8 color filters, 6 morphological filters, and 4 combined filters are applied to the vegetation removal on the embankment slope, and their accuracy and calculation time are compared. Color filters show a short calculation time, but the accuracy was low in the vegetation area. Morphological filters show high accuracy in the vegetation area, but low accuracy in places with severe local topographical changes such as heavy rocks. Combined filters also show a tendency similar to morphological filters, but in the case of ExGGM, the accuracy is excellent in both the vegetation and rock area. Considering the accuracy and calculation time, the combined filter ExGGM is suitable for general cases, and the shape filter GrMIn or the complex filter ExGISL is suitable for cases where the local topographical change is not severe.

• Korean Journal of Ecology and Environment
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• v.48 no.1
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• pp.68-76
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• 2015

There is no willow riparian vegetation in Jeju Island, Korea. Instead, a genetically-isolated population of Adina rubella is found in some parts of the riparian system. We describe its syntaxonomy and synecology. A total of 27 phytosociological relev$\acute{e}$s were collected, 11 relev$\acute{e}$s from 91 sites and 16 relev$\acute{e}$s from the previously published relevant materials. Data were analyzed by traditional Braun-Blanquet method and multivariate PCoA (Principal coordinates analysis). New syntaxa are distinguished, Adinion rubellae all. nov. and its type association Tripogono-Adinetum rubellae ass. nov. with two subassociations, typicum and rhododendretosum poukhanensae. Adino-Rhododendretum poukhanensae Itow et al. 1993 was discarded owing to mismatch of syntaxonomy and syngeography of Adina and Rhododendron phytocoena. The alliance Adinion is Jeju's regional and partly ombrotrophic vegetation occurring in pothole and rock crevice where are independent on ground-water table. We also suggest a revised alliance, Rhododendrion poukhanensae Lee 2004 ex. hoc loco in Korean peninsula, as a corresponding syntaxon to Adinion, which completely differs from Phragmito-Salicion. Finally we pointed out that Adina phytocoena requiring an absolutely monitoring has been threatened by river maintenance project of local government.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.492-507
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• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

• Journal of Korea Water Resources Association
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• v.57 no.8
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• pp.533-548
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• 2024

Due to climate change with extreme weather events, occurrences of unprecedented heavy rainfall have become more frequent. Since it is difficult to perfectly predict and prevent flood damages, the limitation of traditional prevention-centered approaches has come a issue. The concept of "resilience" has therefore been developed which emphasizes the ability to swiftly recover from damages to previous states or to even better conditions. In this study, we 1) developed a total of 20 domestic flood resilience indicators based on the 4R principles (Redundancy, Robustness, Rapidity, Resourcefulness), 2) conducted applicability evaluations targeting specific disaster-prone areas, and 3) assessed the importance of each indicator through Analytic Hierarchy Process (AHP) analysis with flood-related experts. To confirm the suitability of the developed flood resilience indicators, multicollinearity analysis was performed, and the results indicated that all 20 indicators had tolerance limits above 0.1 and Variance Inflation Factors (VIF) below 10, demonstrating suitability as factors. Furthermore, evaluations of proposed indicators were carried out targeting disaster-prone areas in 2022(21 areas), and AHP analysis was utilized to determine the relative importance of each indicator. The analysis revealed that the importance of each indicator was as follows: Robustness 0.46, Rapidity 0.22, Redundancy 0.17, and Resourcefulness 0.16, with Robustness exhibiting the highest importance. Regarding the sub-indicators that had the greatest influence on each 4R component, river embankment maintenance emerged as the most influential for Robustness, healthcare services for Rapidity, fiscal autonomy of local governments for Resourcefulness, and drainage facilities for Redundancy.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.4
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• pp.48-59
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• 2014

This study was carried out to present raw data on managing the restored urban stream by studying the naturalized plants distributed in Gaeumjeong Stream, Changwon-si, Gyeongsangnam-do, Korea. The results were as follows. The numbers of naturalized plants were summarized as 45 taxa including 17 families, 36 genera, 43 species and 2 varieties. The invasive alien plants were 2 taxa including Ambrosia artemisiifolia and Lactuca sativa. The following summarizes the attributes of the naturalized plants. Most of the plants commonly originated from Europe and North America. The 5 naturalized degree that was widely distributed and had many individual was the most common. Until 1921, after the opening of 1 period was the most common in the introduced period. Section 12 had the highest NI at 41.9%, and the lowest, at 20.5%, in sections 9 and 19 were analyzed. Section 1 had the highest UI at 6.2%, whereas, the lowest, at 2.5%, was calculated in sections 19 and 20. Section 2 showed the highest DI at 16.7%. The first results of the analysis of the causes for the invasion of naturalized plants on the riverside and waterways, and physical factors and maintenance are directly affected. Second, sewage, muddy water and sediment deposits this naturalized plant caused by a chemical factor. Third, it is thought that invasive alien plants are irregular as it happens in biological factor. The proposed management plan naturalized plants, the first, disturbance caused by species management is a young object is removed immediately before flowering scape to eliminate or suppress the propagation of physical methods will be needed. Second, the fact that the national spread of native plant species and planting management does not provide space for the growth is very important. Third, agricultural land is disturbed by agricultural practices by interfering with the action of naturalized plants because the source of the river should be prohibited in agriculture. In the future, if we studied the naturalized plants distributed in restored streams located in Changwon-si, the characteristics of change in the ecosystem impact is expected to be beneficial.