• Water for future
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• v.8 no.1
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• pp.61-79
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• 1975

An attempt is made to develope a scheme for synthesizing unit hydrograph for any arbitrary small watershed in the Han or Geum River basin, which can be applied in determining various sizes of design flood for flood control prijects. Stage gauging stations, seven in the Han and five in the Geun River basin with rating curves, were selected as subbasins for the analysis. Unit hydrographs of 2-hour duration were derived for several heavy storm events using the storm and the corresponding flood runoff data for each subbasin. The Clark method programmed by the Hydrologic Engineering Center, U.S. Corps of Engineers, was utilized for derivation of instantaneous unit hydrographs which were, in turn, converted into 2-hour unit hydrograph. By averaging the 2-hour unit hydrographs from several storm events a representative 2-hour unit hydrograph was determined for each subbasin and hence a separate derivation of dimensionless unit hedrograph was also possible for the Han and Geum River basins. The physiographic characteristics such as stream length, distance to the centroid of each watershed were correlated with the characteristic parameters of the derived unit hydrograph for the subbasins within two large basins. correlation analyses between the characteristic parameters were also made. These correlation analyses resulted a series of four equations and a dimensionless unit hydrograph for the two large basins, which made it possible to draw a synthetic 2-hour unitgraph for any small watershed within the Han or Geum River basin. A detailed procedure for aplying the derived method for an arbitrary basin is summarized with one sample computation for each of the two basins. A comparison of the actually derived 2-hour unit hydrogrograph and the synthesized one showed a fair agreement. A recommendation is made for the further study.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.93-93
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• 2020

미래 기후변화로 인해 집중 호우, 가뭄의 발생 빈도가 증가하고, 물 부족, 수질 오염 등으로 인해 합리적인 수자원 계획 및 관리의 중요성이 증가하고 있다. 기후변화는 유역간 물 이동량 뿐만 아니라 유역의 하천 유량 및 수질에 영향을 미치기 때문에, 물 이동량이 많은 유역에서는 기후변화 시나리오를 고려한 하천 유량 및 수질 변화를 정량적으로 평가해야 한다. 만경강 유역(1,602 ㎢)은 하류 지역에 비옥한 평야가 분포되어 있어 농업이 발달한 유역이나, 유역 내 가용 용수가 부족하여 인근에 위치한 금강 용담댐의 발전용수를 공급받아 사용하고 있다. 발달된 농경지로부터 발생되는 비점오염, 축산 점오염원으로 인한 수질 문제가 심각할 뿐만 아니라, 만경강의 수질은 궁극적으로 새만금호에 영향을 미치기 때문에 더욱 엄격한 관리가 필요하다. 따라서, 본 연구에서는 유역간 물이동량, 취수량 등을 고려하여 Soil and Water Assessment Tool(SWAT) 모형을 구축하였다. 2개의 수위-유량 관측소의 일자료와 2개의 수질관측소 월자료를 이용하여 보정(2012~2014) 및 검증(2016~2018)을 수행한 결과 유출량의 평균 Nash-Sutcliffe model Efficiency (NSE)는 0.49 ~ 0.51, SS, T-N, 그리고 T-P에 대한 평균 결정계수(Coefficient of determination, R²)는 0.73, 0.78, 0.72였다. 미래 기후변화에 따른 유역의 수문 및 수질 변화 분석을 위해 증발산량 산정이 가능한 RCP 8.5 기후변화 시나리오에 STARDEX를 활용하여 가장 습윤한 시나리오 및 가장 건조한 기후변화 시나리오를 각각 1개를 선정할 것이다. 선정된 시나리오를 구축된 SWAT 모형에 적용하여 미래 유역간 물이동이 유역의 하천 유량 및 수질에 미치는 영향을 미래 평가기간(S1:2011~2040, S2:2041~2070, S3:2071~2100)으로 구분하여 분석할 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.615-625
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• 2008

In this study, classification of streams was conducted for Ji Stream, a tributary to the Geum River and Yo Stream, a tributary to the Seomjin River, and in addition, channel evolution model to the same streams was applied. The classification approaches suggested by Rosgen and Korea Institute of Construction Technology (KICT) were conducted. The channel evolution model suggested by Schumm et al. (1984) was applied. Based on the application results of Rosgen approach, Ji Stream and Yo stream show the characteristics of mountainous stream with pebbles. The application results of channel evolution model indicated that the current condition of Ji Stream and Yo Stream is a state of equilibrium, balancing the sediment supply and sediment transport capacity. The results of this study can be used as a fundamental data for water control project, river restoration and appropriate channel planning.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.42-42
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• 2022

본 연구는 한반도의 중심 생태 축인 백두대간의 최북단이자 산림유전자원보호구역인 향로봉(1296m) 및 칠절봉(1172m), 둥굴봉(1305m)의 관속식물상을 조사하여 생태적 가치를 연구하고 생물 종 다양성 보전을 위해 진행하였다. 향로봉을 중심으로 2021년 6월부터 2022년 8월까지 총 5회 현장 조사를 실시한 결과, 총 70과 181속 237종 12아종 21변종 1품종 등 총 271분류군으로 확인되었다. 산림청 지정 희귀식물은 총 7분류군으로, 멸종위기(CR) 등급은 날개하늘나리, 끈끈이장구채, 봉래꼬리풀로 3분류군, 취약(VU) 등급은 만삼, 금강초롱꽃 등 2분류군, 위기(EN) 등급은 두메닥나무, 국화방망이로 2분류군이 확인되었다. 북방계식물은 껍질용수염, 개시호, 만삼 등 80분류군으로, 전체 분류군 중 28.8%를 차지하는 것으로 확인되었다. 한국특산식물은 한라사초, 할미밀망, 토현삼 등 17분류군이 확인되었다. 외래식물은 서양민들레, 애기수영, 토끼풀 등 11분류군이 확인되어 전체 분류군 중 3.9%를 차지하는 것으로 나타났다. 확인된 식물구계학적 특정식물 중 V급은 날개하늘나리, 솜다리 등 2분류군으로 나타났으며, 그 외 IV급 15분류군, III급 25분류군, II급 38분류군, I급 14분류군이 확인되었다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.4
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• pp.199-213
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• 2008

Saemangeum salt-water Lake has been created by the completion of the sea-dike in April 2006. To monitor the water qualities of the lake during the sea-dike construction, salinity, SS, nutrients(DIN, DIP, DISi), and chlorophyll-$\alpha$ was analyzed for the surface water from 1999 to 2007. Due to the dike construction, weaker tidal current and lesser resuspension of bottom sediment resulted in the marked decrease of the concentrations of SS in the lake water. Consequently the clearer lake water has provided better condition for primary production with deeper penetration of sunlight into the water column and sufficient nutrient content in the water. Finally the chlorophyll-$\alpha$ content became approximately double in the concentration after the dike construction. Highly stimulated algal production with the marked decrease of the concentrations of SS was decreased the concentration of DIP in the surface water. On the other hand the concentration of DIN and DISi in surface water was increased after dike construction due to the expansion of the freshwater and the supply from bottom layer. As a result, the lake revealed an extremely high NIP ratio and a DIP-limited ecosystem. The lake has been transformed from a typical coastal ecosystem to a brackish one. Since the dike completion, the lake has shown a similar change pattern to the Geum River estuary. Due to the salt-wedge intrusion of seawater, it is highly probable to expect the formation of low-oxygen zone at the bottom layer near the river-mouth area of the lake during the summer. Therefore we need a continuous sentinel monitoring of bottom water qualities in the near future.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.143-152
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• 2008

This study was conducted to obtain basic information on mainstem, branch and leaf characteristics related to canopy for development of high yielding cultivar using 70 Korean soybean cultivars developed from 1913 to 2000. Variations of canopy width, branch length, and canopy width/length ratio were higher compared to other characteristics among 12 mainstem and branch characters. Variations of petiole angle, leaflet width/length ratio and compound leaf dry weight were higher than other characteristics among eight leaf characters related to plant canopy. Three classifications of soybean cultivars were used based on usage: I)soy sauce and tofu, II)bean sprout, and III)cooking with rice. Canopy width/length ratio was higher in group III, cooking with rice than group I, soy sauce and tofu, and group II, bean sprout, and there was no difference between the two, group I and group II. The total branch length/main stem height ratio was higher in group II, bean sprout and group III, cooking with rice than group I, soy sauce and tofu. Mainstem and branch characteristics related to plant canopy were classified into four groups by ratio of canopy width/length and total branch length/main stem length, respectively. Soybean cultivars with narrow canopy and high dependence of mainstem were Danweonkong, Keumkangkong, Shelby, and Shinpaldalkong. Soybean cultivars with broad canopy and high dependence of mainstem were Kanglim, Keumkangdaelip, and Jinyulkong, and a cultivar with broad canopy and high dependence of branch were Geomjeongkong 2. Leaflet length/width ratio was lowest in cooking with rice and there was no difference between soy sauce and tofu and bean sprout. Compound leaf area was largest in cooking with rice and smallest in bean sprout. Leaf petiole length was short in bean sprout and there was no difference between soy sauce and tofu and bean sprout. Leaf petiole angle was highest in cooking with rice and lowest in bean sprout. Leaf type was classified into four groups based on leaflet width/length ratio and compound leaf area, respectivly. Buseok and Taekwangkong had an oval leaflet and largest area of compound leaf. Eunhakong and Sohokong had extreme narrow leaflet and smallest area of compound leaf. Leaf petiole type was classified into three and four groups based on leaf petiole length and angle, respectively. A soybean cultivar with the shortest petiole length and smallest petiole angle was Eunhakong and cultivars with short petiole length and large petiole angle were Alchankong, Muhankong, and Pureunkong. A soybean cultivar with long petiole length and small petiole angle was Sinpaldalkong 2. Among a total of 70 Korean soybean cultivars, Eunhakong had an extreme narrow type in leaf, smallest compound leaf area, shortest petiole length, and smallest petiole angle of compound leaf.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.280-290
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• 2021

The present study investigated species richness and phytoplankton community structure in lakes in the Geum River Basin during autumn and spring seasons. Surveys were conducted between September and November 2019, and between April and May 2020, which corresponded to the autumn and spring seasons, respectively, to explore the distribution characteristics of the species. A total of 49 species of phytoplankton belonging to 31 genera and seven classes were identified in Cho Pyeong-ji, 51 species belonging to 29 genera and six classes were identified in Song Ak-ji, 49 species belonging to 32 genera and seven classes were identified in Cheong Cheon-ji, 82 species belonging to 45 genera and six classes were identified in Ye Dangji, and 70 species belonging to 40 genera and six classes were identified in Ganwol Lake. A total of 43 species belonging to 74 genera and seven classes were identified. The ranges of phytoplankton standing crop were as follows: 223~3533 cells mL^-1 in Cho Pyeong-ji, 881~176018 cells mL^-1 in Song Ak-ji, 402~6139 cells mL^-1 in Cheong Cheon-ji, 262~10460 cells mL^-1 in Ye Dang-ji, and 20413~330695 cells mL^-1 in Ganwol Lake. Phytoplankton diversity in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 1.10~2.60, 0.56~2.03, 0.21~2.03, 0.65~2.57, and 0.44~1.12, respectively. Phytoplankton species richness in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 1.91~4.99, 1.82~3.26, 1.26~4.17, 2.07~5.37, and 1.90~2.43, respectively. Phytoplankton evenness indices in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 0.38~0.78, 0.18~0.69, 0.08~0.71, 0.22~0.72, and 0.14~0.38, respectively. Phytoplankton dominance indices in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 0.40~0.83, 0.55~0.96, 0.44~0.99, 0.42~0.93, and 0.89~0.97, respectively.

• Journal of the Korean Geographical Society
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• v.38 no.5
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• pp.686-700
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• 2003

In Korea, aside from their official administrative names, aliases of each province or some regions are widely used not only today but also during the Joseon period when the provincial system as local administrative system was firmly implemented. Of aliases, the most representative were Giho, Gwandong, Hoseo, Haeseo, Honam, Yaeongnam, Gwanseo, and Gwanbuk representing the eight provinces (precisely, Gyeonggi and seven provinces) of Chosun Dynasty, as well as Yeongdong and Yeongseo that represent the east and the west of Gangwon-do. These aliases are mostly based on topographical features and physiographical elements, and compared to the official names of eight provinces which depended solely on city names. Of aliases, some appeared in literature during 13-l4th centuries, and all provincial aliases seem to have been widely used after the late 15th century. Aliases continued to be used for 500 to over 700 years. Aliases of eight provinces, geographically, played not lesser role than their official names. Aliases of the eight provinces and regions during the Chosun Dynasty that have been handed down are considered as holding their places' cultural and historical backgrounds, and have become important enough to be accepted as a unit of geographical regional division. The origin and meaning of aliases of each province have been partially disclosed to the geographical circle and the general public. However, the details should be reviewed. First of all, Gwan in Gwanbuk, Gwanseo and Gwandong, as well as Yeong in Yeongnam, Yeongdong and Yeongseo, are each considered as meaning Sobaek Mountain Range and Taebaek Mountain Range with many borderline areas (borders) and military strategic hubs. Also, Ho in Honam, Hoseo, and Giho, are considered as based on the Geum River and Eurimji, and Haeseo are considered as meaning the west of the Gyeonggi Bay, and having relevancy with the first letters of Haeju and Seoha (Pungcheon).

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.338-347
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• 2008

Grazing rate (GR) and feces production (FP) of freshwater snail Cipangopaludina chinensis malleata on two hibernal diatom communities were examined in a laboratory. Snail with the similar size (4.2$\sim$5.8 cm) were collected from the Gunsan and Okgu district (Jeonbuk), transferred to the artificial management system in laboratory, and starved for 3 day before the experiment. The feeding experiments were conducted at various conditions such as passage of time (0, 1, 4 and 7 hr), snail density (0.0, 0.5, 1.0, 2.0 and 4.0 ind. $L^{-1}$) and kinds of prey (cold lake and stream water). One prey used in this study is the water of Lake Ilgam, the other is that of Han river. Lake Ilgam water was dominated by Synedra ulna (69.1%) and Scenedesmus sp. (6.6%), while Han river was by Asterionella formosa (69.4%) and Diatoma vulgare (27.7%). With the increment of snail density and time, the Chl-a concentration of two experimental waters were clearly decreased. Chl-a of Han river rapidly was decreased after 1 hour of snail treatment, while that of Ilgam lake was decreased after 4 hour. On the passage of time, a highest GR (1.94 L $g^{-1}\;h^{-1}$) showed at 1 hr, and then, decreased gradually to 0.04 L $g^{-1}\;h^{-1}$ by 7 hr. The highest FP (0.11 mg $L^{-1}$) showed at 7 hr. These results indicate that native snail Cipangopaludina chinensis malleata may be applied as a potential bio-filter to control diatom blooms in the cold lake and stream.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1149-1155
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• 2010

This study was conducted to investigate the changes of quality characteristics, and mineral, oxalate and phytate content during soymilk process. The yields of soymilk ranged from 8.43 mL/g in Bokwangkong to 9.15 mL/g in Bongeuikong and Hannamkong, and total soluble solid contents were ranged from $4.37^{\circ}Brix$ in Anpyeongkong to $7.17^{\circ}Brix$ in Bongeuikong, respectively. The pH and total acidity of soymilk ranged from 6.43 to 6.86 and from 1.48% to 1.65%, respectively. The viscosity of soymilk was the highest value of 20.80 cP in Hannamkong and the lowest value of 15.73 cP in Dawonkong. The highest value of calcium content of soymilk was 1.589 mg/g in Seonheukkong, and oxalate and phytate in soymilk were high at 2.14 mg/g in Hannamkong and 2.18 mg/g in Anpyeongkong, respectively. The transfer ratio of oxalate from soybean to soymilk was the highest value of 77.6% in Jinpumkong 2, and one of the phytate was the highest value of 87.5% in Dongpuktae and the lowest value of 13.9% in Hojangkong.