• Journal of Species Research
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• v.2 no.2
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• pp.159-166
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• 2013

Typical of large, oligotrophic lakes, Lake H$\ddot{o}$vsg$\ddot{o}$l, Mongolia, exhibits complex morphometry which should support a spatially heterogeneous community of benthic macroinvertrates. The lake also exhibits a broad range of land uses. Based on the variation in land use and complex physical habitat of the lake (e.g. substrate variation and presence of affluent streams in bays), we asked two questions. First, does density of total benthic macroinvertebrates vary between different bays in Lake H$\ddot{o}$vsg$\ddot{o}$l? Second, does density of individual benthic taxa vary by bay? Samples collected in 1997, the last year for benthic sampling of the lake, were designed to test for variation in macroinvertebrate density between bays and can now be used to establish baseline variation in density for future studies. A total of 56 Ponar grab samples were analyzed from six bays in Lake H$\ddot{o}$vsg$\ddot{o}$l. Results of a general linear model analysis of variance showed that total density of macroinvertebrates varied only slightly between bays of the lake, but that most individual taxa showed significant variation between bays. Variation in density for most taxa was linked to substrate composition rather than other geographic or physical variables in the lake. Recent increases in grazing intensity and ecotourism along the shores should be managed to reduce the nutrient load into the lake to avoid impairment of the benthic biota of this unique, ancient ecosystem.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.866-881
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• 2012

Han River is a complex water system consisting of many lakes. The water quality of Lake Paldang is significantly affected by incoming flows, which are the South and North branches of the Han River, and the Kyungan Stream. In order to manage the water quality of the Lake Paldang, we should consider the entire water body where the incoming flows are included. The objectives of this study are to develop an integrated river and lake modeling system for Han River system using a multidimensional dynamic model and evaluate the model's performance against field measurement data. The integrated model was calibrated and verified using field measurement data obtained in 2007 and 2008. The model showed satisfactory performance in predicting temporal variations of water level, flow rate and temperature. The Root Mean Square Error (RMSE) for water temperature simulation were $0.88{\sim}2.13^{\circ}C$ (calibration period) and $1.05{\sim}2.00^{\circ}C$ (verification period) respectively. And Nash-Sutcliffe Efficiency (NSE) for water temperature simulation were 1089~0.98 (calibration period) and 0.90~0.98 (verification period). Utilizing the validated model, we analyzed the spatial and temporal distributions of temperature within Han River system. The variations of temperature along the river reaches and vertical thermal profiles for each lakes were effectively simulated with developed model. The suggested modeling system can be effectively used for integrated water quality management of water system consisting of many rivers and lakes.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.184-198
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• 2014

For estimating discharge and pollution loads into the Yeongsan lake, a conceptual watershed model HSPF(Hydrological Simulation Program - Fortran) was applied to the Yeongsan River Basin. Various spatial data set including DEM, watershed boundaries and land uses were used to set up the model for the Yeongsan River Basin that was divided into 45 sub-basins. The model was calibrated and validated for the river discharges, SS, BOD, TN and TP concentrations against the data observed in 2011 at several monitoring stations. The simulation results show good agreement with the observed water flows($R^2$ = 0.46 - 0.97, NSE = 0.70 - 0.96). The simulated concentrations of SS, BOD, TN and TP are also in good agreement with the observed. The total freshwater discharge to the Yeongsan lake is estimated $2,406{\times}10^6m^3/year$ which the Jiseok and Hwangryoung stream contribute as much as 19%, 17% respectively. It is estimated that the total discharges to the Youngsan lake is SS 152,327 ton/year, BOD 15,721 ton/year, TN 10,071 ton/year, TP 563 ton/year. Both water and pollution loads are high in summer, particularly in July, when the monsoon season arrives at the Korean peninsula.

• Journal of Environmental Impact Assessment
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• v.9 no.4
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• pp.291-300
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• 2000

Juam lake is a major water reservoir for the industrial and agricultural activities as well as the residental life of Kwangju and Chonnam regions. However, the water quality of the lake is getting worse due to a large quantity inflowing to the lake. The excessive growth of algae by the overfertilization may result in water treatment problems and also the interference with desirable water uses of navigation, aesthetics, recreation, and aquatic ecosystem. Thus the purpose of this study is to investigate the species and their amount of planktons in the lake and the relationship between the P loading amount and the chlorophyll-a used as a primary productivity index. The results of the investigation show that (1) the predominant species of algae are Microcystis aeruginosa, Anabaena affinis, Melosira granulata, Synedra acus, and Coelastrum cambricum, (2) the trophic state of the lake can be classified as eutrophic, and (3) there is close relation between the P loading amount and the chlorophyll-a.

• Korean Journal of Environmental Biology
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• v.22 no.4
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• pp.524-531
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• 2004

Photosynthetic activities and primary production of phytoplankton were investigated in Lake Gocheonam from October 1999 to August 2000. As an estuary lake with a barrage in the Southwestern coast of the Korean peninsula, the lake has received more attention after it became known as the habitat of large population of rare and endangered bird- Baikal Teal. As the lake had high algal biomass ranging from $20\mu{g}\;chl-aL^{-1}\;to\;125\mu{g}\;chl-aL^{-1}$ in average values and rich eutrophication indicator species, the freshwaters were in a very productive or hypertrophic state. In the results obtained from the phytoplankton incubation in the laboratory, the maximum photosynthetic rate $(P_{max})$ varied according to seasons and sampling stations. Photo- synthetic activities were higher during the warm season than the cold seasons and the serial order of $P_{max}$ was August dominated with Microcystis, April with Chlamydomonas and Nitzschia, October with Chlamydomonas and January with Stephanodiscus. The water of the lake was persistently turbid throughout the year due to strong winds from the adjacent sea. Despite the water turbidity, the phytoplankton productions estimated from a mathematical model had very broad range from 18mg C $m^{-2}day^{-1}\;to\;10,300mg\;C\;m^{-2}day^{-1}$.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.75-75
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• 1995

In order to provide for the guidance on groundwater quality monitoring network design and also, to suggest the index to the solution of the contaminated groundwater remediation problems in the lake watershed, it is necessary to analyze the contaminant transport in the groundwater. The solute transport was analyzed in the lake watershed to investigate the behavior of the injected contaminant sources depend on the relationships between the point of contaminant sources and position of the lake. Three hypothetical groundwater flow systems, which is composed of a flow-through lake and two solute sources, were considered. The lakes located in the upper, middle, and lower portions of a watershed respectively. The transported contaminant was numerically simulated for five years by using MT3D contaminant transport model under the three-dimentional steady state conditions. From the above simulations, it can be concluded that the contaminant concentration was high as the contaminant source located at the upper position of a watershed, and the influence of the contaminant injection was large as the solute source located at the lower position. When the injection of contaminant was continued for one year without regard to the position of contaminant source and the lake, the influence of contaminant source was reached to bedrock.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.461-468
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• 1995

In order to provide for the guidance on groundwater quality monitoring network design and also, to suggest the index to the solution of the contaminated groundwater remediation problems in the lake watershed, it is necessary to analyze the contaminant transport in the groundwater. The solute transport was analyzed in the lake watershed to investigate the behavior of the injected contaminant sources depend on the relationships between the point of contaminant sources and position of the lake. Three hypothetical groundwater flow systems, which is composed of a flow-through lake and two solute sources, were considered. The lakes located in the upper, middle, and lower portions of a watershed respectively. The transported contaminant was numerically simulated for five years by using MT3D contaminant transport model under the three-dimentional steady state conditions. From the above simulations, it can be concluded that the contaminant concentration was high as the contaminant source located at the upper position of a watershed, and the influence of the contaminant injection was large as the solute source located at the lower position. When the injection of contaminant was continued for one year without regard to the position of contaminant source and the lake, the influence of contaminant source was reached to bedrock.

• Smart Media Journal
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• v.7 no.4
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• pp.30-36
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• 2018

Single domain model like DataLake framework is in spotlight because it can improve data efficiency and process data smarter in big data environment, where large scaled business system generates huge amount of data. In particular, efficient operation of network, storage, and computing resources in logical single domain model is very important for physically partitioned multi-site data process. Based on the advantages of Data Lake framework, we define and extend the concept of Connected Data Architecture and functions of DataLake framework for integrating multiple sites in various domains and managing the lifecycle of data. Also, we propose the design of CDA-based AI service and utilization scenarios in various application domain.

• The Korean Journal of Applied Statistics
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• v.16 no.1
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• pp.15-31
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• 2003

In this study, we will construct a statistical model which considered the irregularity of observed time sequence in order to analyze sets of bioindex data gathered from stations in Lake Ontario for a number of years. We fit a linear model to account for the trend and seasonal component in an exploratory way and draw variogram and correlogram for further confirmatory studies.

• Journal of Korea Water Resources Association
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• v.30 no.6
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• pp.649-659
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• 1997

The influence of polluted water discharged from the Saemankeum Lake is predicted by using two-dimensional finite element model. The simulation results show that influence of the Polluted water to the northern part of the Kckunsan Islands is small during flood time. The reason is because lock gates are located in the south of the Kokunsan Islands so that tidal current directing north is blocked by these Islands. However, during the ebb time, the influence of the polluted water is extended to the whole southern part of the Kokunsan Islands. When the amount of ten percent of the total volume of polluted water is discharged from the Saemankeum Lake, equi-concentration contour line of one tenth of initial discharge concentration includes the inner area surrounded by Sinsi Island, Munyeo Island, Bian Island, and Daehang-Li. In general, peak concentration near the lock gates is found out to be higher during the spring tide than the neap tide.