• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.289-298
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• 2006

The purpose of this study was to investigate salt marsh flora and vegetation in the mouth of Mankyeong river estuary area where has a project for Sea Man Geum Reclaimed Land so that we can foster a foundation on restoration of an ecological habitat, development of applicable plants and establishment of a conservation policy after developing the reclaimed land for salt marsh vegetation which has great ecological value. As a result of this research, there are 10 families 25 genera 29 species and 3 varieties of vascular plants in the Mankyong-river estuary area. These are 0.76% among 4,191 of Korean vascular plants. There are also 5 families 6 genera 6 species and 1 varietiy of the naturalized plants which are 7 taxa in total and 3.85% of indicators of naturalized plants. Firstly, a district of low tide marsh has below 5% of vegetation coverage of Suaeda japonica and the vegetation cover was increasing rapidly while moving to a place of high tide marsh which is in the direction to a bank. In general, a range of from low tide marsh to high tide marsh is distributed with sequence of Suaeda japonica$\rightarrow$Suaeda maritima$\rightarrow$Suaeda japonica$\rightarrow$Aster tripolium$\rightarrow$Artemisia scoparia$\rightarrow$Carex scabrifolia$\rightarrow$Zoysia sinica$\rightarrow$Phragmites australis$\rightarrow$Phacelurus latifolius. Suaeda japonica has the highest dominance among the species composition and Aster tripolium, Phragmites australis, Artemisia scoparia, Carex scabrifolia and Phacelurus latifolius are distributed as zonation or patch. By the Z-M method eleven plant communities were recognized; Suaeda japonica, Suaeda japonica-Suaeda maritima, Suaeda maritima, Suaeda japonica-Aster tripolium, Aster tripolium, Phragmites australis, Carex scabrifolia, Phacelurus latifolius, Artemisia scoparia-Aster tripolium, Paspalum distichum var. indutum and Aster tripolium-Artemisia scoparia community. The actual vegetation map was constructed of the grounds of the communities classified and other data.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.836-841
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• 2012

Distributions and growth of submerged plants with water level were investigated in a flood control reservoir around Dongbok Lake. In adddition, the total amount of biomass and uptakes of plants per unit area ($m^2$) in the flood control reservoir were investigated. The total vegetation area was $156,871m^2$ in the Dongbok flood control reservoir ($209,160m^2$) before flooding. By July 11, the Dongbok flood control reservoir was flooded during rainy season except for upper area. Dominant plants were CRXDM (Carex dimorpholepis Steud), ECHCF (Echinochloa crusgalli), POLHY (Polygonum hydropiper L) and BROTE (Bromus tectorum L) which occupied 75% of the flood control reservoir. The total amounts of organic matter uptakes per unit area ($m^2$) with distribution rates by CRXDM, ECHCF, POLHY and BROTE under different submerged plants were 65.5, 6.8, 7.0 and 13.0%, respectively. The total amount of nitrogen uptakes per unit area ($m^2$) with distribution rates at different submerged plants were in the order of CRXDM ($1.30g\;m^{-2}$) > POLHY ($0.34g\;m^{-2}$) > BROTE ($0.30g\;m^{-2}$) > ECHCF ($0.25g\;m^{-2}$). The total amounts of phosphorus uptakes per unit area ($m^2$) with distribution rates at different submerged plants were great in the order of CRXDM (51.8%) > BROTE (17.7%) > POLHY (10.3%) > ECHCF (9.6%). Thus, the results of this study suggest that O.M, T-N and T-P by submerged plants in Dongbok Lake were strongly influenced at water quality in flood control reservoir.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.35-46
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• 2009

In order to investigate spatial and temporal distributional characteristics of major water qualities in the Saemangeum area during the Saemangeum dike construction, salinity, COD, dissolved nutrients(DIN, Silicate) and heavy metals were analyzed from the surface water collected in April, May, August and November 2002. The overall value of Salinity, COD, DIN, and silicate in surface waters were in the range of $13.08{\sim}31.96\;psu$, $0.12{\sim}3.43\;mg/L$, $0.001{\sim}2.638\;mg/L$, and $0.010{\sim}3.181\;mg/L$, respectively. The COD and DIN in each survey showed the highest concentration at the mouth of Mangyeong river estuary(St. 1) where freshwater flow into the Saemangeum area. The concentrations of nutrients were high in the inner part of the Saemangeum dike with low-salinity, and low nutrients in the outer part of the dike with high-salinity, which strongly indicated that concentrations were adjusted by physical mixing. The ranges of dissolved metals and acid-soluble Hg in surface seawater were $0.006{\sim}0.115{\mu}g/L$ for Co, $0.26{\sim}0.114{\mu}g/L$ for Ni, $0.14{\sim}0.93{\mu}g/L$ for Cu, $0.04{\sim}0.53{\mu}g/L$ for Zn, $0.010{\sim}0.043{\mu}g/L$ for Cd, $0.010{\sim}0.795{\mu}g/L$ for Pb, and $0.25{\sim}4.16{\mu}g/L$ for Hg. The highest concentrations of some metals except for Cd were found at the estuary(Sts. 1 or 3). In most cases, a decreasing order of metal concentrations towards open sea(low-salinity$\rightarrow$high-salinity) was observed and showed positive relationship with DIN and silicate caused by land base pollutants input. On the other hand, due to Cd desorption from suspended solids in saline water, dissolved Cd concentrations were high in high-salinity area and low in low-salinity. In November, Co, Zn, Cu and Pb were relatively high in the northern area of the outer-side of Saemangeum, which was only influenced by the Geum river discharge. The concentrations of most dissolved metals of this study were lower than those of the past data in this area, but higher than those in Lena river estuary under the pristine environment.

• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.597-611
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• 2013

This paper presents the methodology for construction of time-area curve via the width function and thereby rational estimation of time of concentration and storage coefficient of Clark model within the framework of method of moments. To this end time-area curve is built by rescaling the grid-based width function under the assumption of pure translation and then the analytical expressions for two parameters of Clark model are proposed in terms of method of moments. The methodology in this study based on the analytical expressions mentioned before is compared with both (1) the traditional optimization method of Clark model provided by HEC-1 in which the symmetric time-area curve is used and the difference between observed and simulated hydrographs is minimized (2) and the same optimization method but replacing time-area curve with rescaled width function in respect of peak discharge and time to peak of simulated direct runoff hydrographs and their efficiency coefficient relative to the observed ones. The following points are worth of emphasizing: (1) The optimization method by HEC-1 with rescaled width function among others results in the parameters well reflecting the observed runoff hydrograph with respect to peak discharge coordinates and coefficient of efficiency; (2) For the better application of Clark model it is recommended to use the time-area curve capable of accounting for irregular drainage structure of a river basin such as rescaled width function instead of symmetric time-area curve by HEC-1; (3) Moment-based methodology with rescaled width function developed in this study also gives rise to satisfactory simulation results in terms of peak discharge coordinates and coefficient of efficiency. Especially the mean velocities estimated from this method, characterizing the translation effect of time-area curve, are well consistent with the field surveying results for the points of interest in this study; (4) It is confirmed that the moment-based methodology could be an effective tool for quantitative assessment of translation and storage effects of natural river basin; (5) The runoff hydrographs simulated by the moment-based methodology tend to be more right skewed relative to the observed ones and have lower peaks. It is inferred that this is due to consideration of only one mean velocity in the parameter estimation. Further research is required to combine the hydrodynamic heterogeneity between hillslope and channel network into the construction of time-area curve.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.126-141
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• 2021

Fauna of freshwater fish and community structure were investigated at 13 sites in the Deogyusan National Park, Korea from 2014 to 2018. During the period, a total of 8 families, 21 species, and 8,716 individuals of fishes were collected. The number of fish collected over the past five years from 2014 to 2018, were 17 species and 2,280 individuals, 17 species and 1,579 individuals, 17 species 1,905 individuals, 17 species and 1,384 individuals, and 15 species and 1,568 individuals, respectively. There were 13 Korean endemic species including Iksookimia koreensis and Coreoleuciscus splendidus, etc. Only in Wondangcheon Stream, two endangered species were identified, and Hemibarbus mylodon was collected continuously except in 2015, and Pseudopungtungia nigra was observed every year. And two exotic species such as Oncorhynchus masou masou and Oncorhynchus mykiss occurred in Gucheongdongcheon Stream sites. The dominant species was Rhynchocypris oxycephalus and the sub-dominant species was Zacco koreanus and there was no difference by year. The fish community structure of Deogyusan National Park was varied depending on the sites and the year. Most of the survey sites located upper stream where the river structure is Aa river type showed poor community analysis results. On the other hand, the upper-mid stream sites including the Bb type showed better results. As a result, the Wondangcheon Stream sites had the most diverse and stable community structure. Similarity dendrogram was divided into 4 groups, mainly reflecting the characteristics of the habitat. The flagship species of the Deogyusan National Park, Rhynchocypris kumgangensis, was constantly observed during the investigation period. Compared to the previous survey, the number of species increased from 2004 (12 species) and decreased from 2009 (22 species).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.3
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• pp.154-163
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• 2005

Irregular discharges of freshwater through the water gates of the Keum River Estuarine Weir, Korea, whose construction had been completed in 1998 with its water gates being operated as late as August 1994, drastically modified the estuarine environment. Sharp decrease of salinity along with the altered concentrations of inorganic nutrients are accompanied with the irregular discharges of freshwater into the estuary under the influence of regular semi-diurnal tidal effect. Field sampling was carried out on the time of high tide at 2 fixed stations(St.1 near the Estuarine Weir and St.2 off Kunsan Ferry Station) every other day for 4 months from mid-February 2004 to investigate into the semi-weekly variation of spring phytoplankton community in relation to the freshwater discharges from Keum River Estuarine Weir. CV(coefficient of variation) of salinity measurements was roughly 2 times greater in St.1 than that in St.2, reflecting extreme salinity variation in St.1 Among inorganic nutrients, concentrations of N-nutrients($NO_3^-,\;NO_2^-$ and $NH_4^+$) were clearly higher in St.1, to imply the more drastic changes of the nutrient concentrations in St.1. than St.2 following the freshwater discharges. As a component of phytoplankton community, diatoms were among the top dominants in terms of species richness as well as biomass. Solitary centric diatom, Cyclotella meneghiniana, and chain-forming centric diatom, Skeletonema costatum, dominated over the phytoplankton community in order for S-6 weeks each (Succession Interval I and II), and the latter succeeded to the former from the time of <$10^{\circ}C$ of water temperature. Cyanobacterial species, Aphanizomenon Posaquae and Phormidium sp., which might be transported into the estuary along with the discharged freshwater, occupied high portion of total biomass during Succession Interval III(mid-April to late-May). During this period, freshwater species exclusively dominated over the phytoplankton community except the low concentrations of the co-occurring 2 estuarine diatoms, Cyclotella meneghiniana and Skeletonema costatum. During the 4th Succession Interval when the water temperature was over $18^{\circ}C$, the diatom, Guinardia delicatula, was predominant for a week with the highest dominance of $75\%$ in discrete samples. To summarize, during all the Succession Intervals other than Succession Interval III characterized by the extreme variation of salinity under cooler water temperature than $18^{\circ}C$, the diatoms were the most important dominants for species succession in spring. If the scale and frequency of the freshwater discharge could have been adjusted properly even during the Succession Interval III, the dominant species would quite possibly be replaced by other estuarine diatom species rather than the two freshwater cyanobacteria, Aphanizomenon flosaquae and Phormidium sp.. The scheme of field sampling every other day for the present study was concluded to be the minimal requirement in order to adequately explore the phytoplankton succession in such estuarine environment as in Keum River Estuary: which is stressed by the unpredictable and unavoidable discharges of freshwater under the regular semi-diurnal tide.

• Korean Journal of Heritage: History & Science
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• v.54 no.4
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• pp.36-59
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• 2021

This study infers the origin and production period of the , which is in the Onyang folk museum, through analysis and interpretation of the Haeju Palgyeong and exploration of the landscapes and traditions contained in the painting. The first collection of landscapes to Haeju was identified as Haeju Palgyeong by Ku Sa-meng (1531-1604). Yoo Man-ju, writing in 1782, referred to it as Go-palgyeong in 『Heumyeong』 while Haeju Palgyeong was defined as Geum-palgyeong (今八景), which is the Haeju Palgyeong in the earliest period confirmed by literature. is 'Boating on the Nam river (南江泛舟)', 'Lotus viewing at Buyongdang (芙蓉賞蓮)', 'Foot washing at Gwangseokcheon (廣石濯足)', 'Seokbyul at Haeunkyo (泣川送客)', 'Fishing at Haeunjeong (東亭釣魚)' and 'Sea view at Namsan( 南山望海)', and the final two contain a picture that contains 'Viewing the moon at Yeonghaeru (瀛海玩月)' and 'Writing contest and Archery at Baeklimjeong (栢林觀德)' The Suyang Chaemi(首陽採薇), Shingwang-jeoljeol (神光霽雪), and Jiseong falls (池城瀑布) of Gopalgyeong, which were excluded from Haeju Palgyeong, are all landscapes unfolding as a grand site of Suyangsan Mountain. is a result of the reorganization of Seunggyeong centered on Eupchi (邑治), away from the Suyangsan area. It has emerged as a seunggyeong of Haeju. The elaborateness of trying to contain the detailed prizes representing Haeju, such as the specialty sake of Haeju, is revealed. Most of the landscapes depicted in are historic and outstanding spots in Haemok, but the scenes of life related to daily life are properly arranged. In addition, Foot washing (濯足), Fishing(釣魚), Doing laundry (漂母), Lotus viewing (賞蓮), Sending guests (送客), Drinking (飮酒), sea viewing (望海), Moon viewing (玩月), Archery (射藝), Poetry (詩作), Drinking tea (飮茶), and Dancing (歌舞) are of various styles. Compared with the Gopalgyeongs, Haeju Palgyeong did not take into account the distribution of landscapes in the four seasons, and the small-sized view was also broken. When considering the time of the construction of Haeunjeong and the deterioration of Yeonghhoeru, it is believed that was produced in the early- to mid-18th century. is considered to be a painting that contributed to strengthening the sense of intimacy with the local people and promoting the pride of Haeju by showing the representative scenery of Haeju, such as scenic spots and customs, away from the ideal utopia.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.153-161
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• 2014

The purpose of this study is to evaluate effect of heavy metals (i.e., $Cu^{2+}$, $Zn^{2+}$, $Cr^{6+}$, $Cd^{2+}$, $Hg^{2+}$, and $Pb^{2+}$) to toxicity of Triclosan as binary mixture. The individual toxicity and combined toxic effects of Triclosan with heavy metals were evaluated by Vibrio fischeri assay. In individual toxicity, the $Hg^{2+}$ was found to be most toxic followed by Triclosan, $Pb^{2+}$, $Cr^{6+}$, $Cu^{2+}$, $Zn^{2+}$, and $Cd^{2+}$, respectively. To evaluate combined toxic effect, correlation analysis of 'predicted value' calculated by Concentration addition (CA) model and Independent action (IA) model with 'experimental value' were performed based on the toxicity of individual compound. As a result, all of the combinations showed that IA model were more correlated with experimental value than CA model. On the basis of the median effect concentration of combination ($EC_{50mix}$) predicted by IA model, experimental $EC_{50mix}$ of Triclosan + Cu, Triclosan + Zn, Triclosan + Pb, Triclosan + Hg, Triclosan + Cd, and Triclosan + Cr were 191%, 226%, 138%, 137%, 209%, and 138% of $EC_{50mix}$ predicted by IA model, respectively, indicating that all of the combinations produced antagonistic effect.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.215-223
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• 2006

The Total Maximum Daily Load(TMDL) Act just implemented as a new tool of watershed based water quality management, in Korea. Thus, there are a number of pending questions to resolve for successful settlement of the TMDL. The allocation of pollution source is a exceedingly sensitive issue on local development planning. The simple area-based allocation (SAA) is conventional method to allocate the administrational pollution information to watershed based information. The SAA has a limitation that it can't consider the characteristics of spatial distribution of pollution source and it has caused more uncertainty of TMDL. This study was performed to reduce the uncertainty of watershed-based pollution information using the spatial distribution-based allocation(SDA). In the specific area where pollution source is concentrated such as urbanized region, it has been certified that SDA could reduce a tolerance of pollution information dramatically. As a result of study, SDA is expected a effective tool for TMDL and to solve the conflict between development and protection.

• 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.