• Journal of Korea Water Resources Association
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• v.50 no.11
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• pp.769-779
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• 2017

As the occurrence of drought is recently on the rise, the reliable drought forecasting is required for developing the drought mitigation and proactive management of water resources. This study developed a probabilistic hydrological drought forecasting method using the Bayesian Networks and drought propagation relationship to estimate future drought with the forecast uncertainty, named as the Propagated Bayesian Networks Drought Forecasting (PBNDF) model. The proposed PBNDF model was composed with 4 nodes of past, current, multi-model ensemble (MME) forecasted information and the drought propagation relationship. Using Palmer Hydrological Drought Index (PHDI), the PBNDF model was applied to forecast the hydrological drought condition at 10 gauging stations in Nakdong River basin. The receiver operating characteristics (ROC) curve analysis was applied to measure the forecast skill of the forecast mean values. The root mean squared error (RMSE) and skill score (SS) were employed to compare the forecast performance with previously developed forecast models (persistence forecast, Bayesian network drought forecast). We found that the forecast skill of PBNDF model showed better performance with low RMSE and high SS of 0.1~0.15. The overall results mean the PBNDF model had good potential in probabilistic drought forecasting.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.245-257
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• 2016

Although rivers cover only 0.5% of the total land area on the Earth, they are windows that show the integrated effects of watershed biogeochemistry. Studies on the loads and properties of riverine carbon have been conducted because they are directly linked with drinking water quality, and because regional or global net ecosystem production (NEP) can be overestimated, unless riverine carbon loads are subtracted. Globally, ${\sim}0.8-1.5Pg\;yr^{-1}$ and ${\sim}0.62-2.1Pg\;yr^{-1}$ of carbon are transported from terrestrial ecosystems to the ocean via rivers and from inland waters to the atmosphere, respectively. Concentrations, ${\delta}^{13}C$, and fluorescence spectra of riverine carbon have been investigated in South Korea to understand the spatiotemporal changes in the sources. Precipitation as well as land use/land cover can strongly influence the composition of riverine carbon, thus shifting the ratios among DIC, DOC, and POC, which could affect the concentrations, loads, and the degradability of adsorbed organic and inorganic toxic materials. A variety of analyses including $^{14}C$ and high resolution mass spectroscopy need to be employed to precisely define the sources and to quantify the degradability of riverine carbon. Long-term data on concentrations of major ions including alkalinity and daily discharge have been used to show direct evidence of ecosystem changes in the US. The current database managed by the Korean government could be improved further by integrating the data collected by individual researchers, and by adding the major components ions including DIC, DOC, and POC into the database.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3345-3350
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• 2014

We investigated to assess the relationships between the major nutrients and phytoplankton dynamics during the spring season in 2010 and 2011 at 23 stations in Jinhae Bay, Korea. The bay is divided into four different zones based on pollutant sources and geographical characteristics. Nutrient limitation (>80%) was significant in Zone II, which is located in central bay and is influenced by the water well mixed from outer bay. The limited nutrient was followed in Zone III and IV that was occupying between 17% and 83%. However, the low levels are being kept below 35% in Zone I, which is characterized by the semi-enclosed eutrophic area of Masan and Haegam bays. Based on the PCA (principle component analysis) analysis, the nitrogen (N) sources in 2010 were particularly dominant and it may be due to the water mixing and wastewater formed from bottom layers and sewage. In 2011, major nutrients including nitrogen, silicon and phosphorus were dominant in the bay and are supplied by the river discharge after rainfalls with low salinity conditions. In particular, the N nutrients being supplied in 2010 are correlated with pennate diatoms Pseudo-nitzchia spp. and is not related to the phytoplankton population densities in 2011. The present study suggests that N sources play an important role in the proliferation of diatom, and the rapid nutrient uptakes by them are potential nutrient limitation factors in the bay.

• The Journal of Korean Philosophical History
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• no.31
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• pp.321-346
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• 2011

This is a preliminary study in order to deal intensively with the overall characteristics of Korean military science in the future days. First off, the history of military science of China based on the precedent studies was recapitulated, and a comparative study on the acceptance process of the books on military art and science, as well as on understanding patterns of literati on the subject through literature searches, ranging from the Three Kingdoms Period to the Goryeo Dynasty in Korean peninsula, was conducted. In case of Korea, the Chinese books on military strategy, including Sun Tzu's the Art of War, had already been passed down during the Three Kingdoms Period, and broadly read by scholarly people. They had utilized diverse methods based on their knowledge of Confucianism. In the reference materials, the authors of Korean military strategy books had greatly relied upon the Chinese books on military strategies, however, they had made the military principles run in their own way. At the end of Goryeo Dynasty, 'Military Science' had been well established as a subject in academia, and this curriculum had been taught not only at the National Confucian Academy, Seonggyun-gwan, in the capital but also at the country public school ("Hyanggyo") in the province together with Confucianism. Because of the limits of reference materials, however, it was difficult to confirm whether or not such strategic experiences were actually led to the publication of the books on military art and science, or how many books on military strategies and tactics had been published up until the end of Goryeo Dynasty. But, the facts that there were not many publications of the books on military strategies during the era of Three Kingdoms and of Goryeo Dynasty don't mean that Korean military science had entirely relied upon the Chinese military art and science. For instance, such strategies, tactics and leaderships as exhibited in the process of the Great Victory at Salsu River ("Salsu Daecheop") achieved by General Eulji Mun-deok, as well as the Great Victory at Gwiju ("Gwiju Daecheop") achieved by General Kang Gam-chan could never happen by chance.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.15-21
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• 2010

We estimated the biomass productivity and the storage potential of nitrogen, the major contributor of non-point source pollution, with four three-year-old four poplar clones in a riparian woody buffer established in the Anseong River in Anseong, Korea. Stem of Populus alba ${\times}$ P. glandulosa clone 72-31 and Populus deltoides ${\times}$ P. nigra clone Dorskamp showed the highest percentage of aboveground biomass components, followed by branch and leaf. Nitrogen content in aboveground biomass components of two poplar clones was the highest in leaf and the lowest in stem. Nitrogen content in leaf and branch of clone 72-31 was higher than that of clone Dorskamp, while it in stem was lower. Populus deltoides clone Ay48 showed the highest above-ground biomass productivity, which was estimated as $37.5ton\;ha^{-1}$ at age 3. However, clone 72-31 was the lowest in above-ground biomass productivity. Nitrogen storage potential in aboveground biomass of 3-year-old poplar clones was high in order of aboveground biomass. Clone Ay48 showed the highest nitrogen storage potential in aboveground biomass, which was estimated as $218.3kg\;ha^{-1}$ at age 3.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.101-115
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• 2013

11 alpine wetlands at the upper reaches of Bangtae River on a high flat summit around Mt. Jeombong were found. Two core samples(JB-1 and JB-2) among them were collected in order to reconstruct paleovegetation history and climate change using pollen analysis. Pinus and Quercus dominated at the wetland of JB-2 with a deep water depth were developed from 1,700 yr BP to 1,000 yr BP of the pollen zone I. Subsequently Quercus dominated in the pollen zone II from 1,000 to 400 yr BP, and it is supposed that warm weather prevailed with oak climax forest corresponding to the Medieval Warm Period. Moreover, sphagnum grew densely in the alpine wetlands and the wetlands were extended widely on the summit around Mt. Jeombong with the beginning of subzoneIIc at JB-2. The pollen zone III from 400 yr BP to the present with an increase in Pinus and a decrease in Quercus suggests cold climates under the Little Ice Age. Moreover, human disturbances at JB-2 were more significant than those at JB-1, based on the increase in Pinus.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.51-68
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• 2012

This paper aims to investigate the value in culture, history and ecology of the Mt. Palgong. It attempts to build the strategy for making use of The Mt. Palgong by literature survey, interview, and field survey. The main results are as follows: 1) The boundary of physical geography of the Mt. Palgong is classified into two. The boundary of the Mt. Palgong limits to granite mass block in a narrow sense, while in a broad sense, the boundary of the Mt. Palgong includes a contact aureole to be bordered on the Mt. Palgong granite mass block. The boundary from a cultural viewpoint limits to Daegu city(excluding Dalseong county) and Gyeongsan city, Yeongcheon city, Gunwi county and Chilgok (Dongmyeong-myeon, Giseong-myeon) in Gyeongbuk province. 2) In the geological boundary, one of the south-west slope is clearer than that of the north-east slope of the Mt. Palgong. The landforms such as tor, sheeting joint and gutter are well developed as a whole. Mountain landform such as boulder stream, polygonal cracking is relatively well developed on the south-west slope, while river landform is relatively well developed on the north-east slope of the Mt. Palgong. 3) It is necessary to develope various masterpiece of interesting stories related to Mt. Palgong in order to make the Mt. Palgong excellent tour complex. 4) It is desirable to designate the Mt. Palgong as a national park for systematic management. A master plan should be ultimately designed to raise brand value of Daegu city, and make good identity of the city by restoring 'The Mt. Palgong Jecheondan' and registering 'Gatbawi' as world heritage. 5) It is reasonable that the method of development in The Mt. Palgong should be based on the pattern of 'slow life town'. 'The Mt. Palgong museum' will then be designed to give visitors all the informations on The Mt. Palgong.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.149-164
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• 2014

The representative landscapes in Jeju Island called as Ten sceneries of Yeongju originates with Ten sceneries of Tamra which were organized in the late seventeenth century by Jeju governor Lee Iktae. In order to compose ten representative sceneries in Jeju Island, he selected four strongholds such as Jocheon, Byeolbang, Seogwi and Myeongwol and six places of scenic beauty such as Seongsan, Baekrokdam, Yeonggok, Cheonjiyeon, Sanbang and Chwibyeongdam, and made a painting named as Ten sceneries of Tamra. Since the scenes of strongholds also exhibit a lot of geomorphic landscapes, the painting could be considered a collection of representative landforms in Jeju Island. The painting depicts several types of landform such as volcano, crater, river, waterfall, pool, wetland, cavern, tor and rocky coast. The volcanic edifice appears most frequently in the painting, reflecting the particular emotion of Jeju people on Mt. Halla and oreums. However, another volcanic landform, a lava tube, was not highly evaluated due to its negative images. Three famous waterfalls in Jeju Island were included in Ten sceneries of Tamra, and it suggests that they are essentially outstanding landforms, and besides, there are few sites related with fresh water in Jeju Island. The ten sceneries were entirely organized in spite of the limitation of selecting places at that time. The landscape images of Jeju Island, which had been shared as collective representation by Jeju people, were firstly externalized through Lee Iktae's painting, and have long been passed down and established a kind of scenic stereotype.

• Ecology and Resilient Infrastructure
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• v.6 no.3
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• pp.163-170
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• 2019

The civil engineering materials used to stabilize the slopes of new riverbanks have a great impact on the types and growth of vegetation introduced after the completion of construction procedure. Recently, microbial-derived, ${\beta}$-glucan- and xanthan gum-based biopolymers are attracting attention as an ecofriendly strengthening material of riverbanks that can possibly stimulate plant growth. This study aimed to assess ecological effects of biopolymer application on native plants in Korean riverbanks. In particular, since dominant plant species could shape characteristics of an ecosystem, we examined the effects of biopolymer on the dominant plant species in riverbanks. Overall, biopolymer did not affect seed germination rates of testing plant species. In contrast, plants grew more vigorously in the soil mixed with biopolymer compared to those in the control soil. The biomass of Echinochloa crus-galli especially increased around two times more in the biopolymer treatment. Plants produced heavier root biomass and leaves with larger specific leaf area, which possibly contributes to the tolerance of environmental stress like drought. These results suggest that biopolymers treated on river banks are expected to stimulate plant growth and increase stress tolerance of domestic dominant plant species.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.1
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• pp.1-20
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• 2021

The purpose of this study was to understand students' representational competence while they engaged in learning in geological field trips with scientific models and modeling(Mt. Gwanak and the Hantan-river were formed). Ten students agreed to participate in this study voluntarily. They were attending the Institute of Gifted Education in the Seoul Metropolitan area. The data were collected for all students' activities during field trips and modeling activities using simultaneous video and voice recording, the interview after classes, written data(note) made by the students. The analysis framework that distinguished levels of representational competence and added the resulting interpretation with the final models in the process of scientific models. Results suggested that representational competence levels varied from one to six. However, students showed relatively low levels of representational competence in outdoor learning environments than indoor learning environments. In other words, it began with a relatively low level of representational competence in outdoor class. Then students developed a higher level of representational competence indoor class. Ultimately, we need to understand students' representational competence implies a tool to explain phenomena in the process of modeling activities.