• Journal of Ecology and Environment
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• v.36 no.1
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• pp.95-100
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• 2013

Many countries have adopted a single, well-described approach to the use of phototrophs for monitoring river water quality, which involves the use of indices related to diatom composition at a site. Increasingly these indices have focussed on assessing ambient phosphate concentration. However, there is a wide range of other methods which can provide additional information to make up for any weaknesses in the standard method. Some of these methods are reviewed briefly here. They can be useful, for instance, when considering temporal and spatial variability in phosphate concentration at a particular site and providing much more insight on heavy metal or pesticide pollution than revealed by routine water analysis.

• Journal of the Korean Institute of Rural Architecture
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• v.15 no.4
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• pp.69-78
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• 2013

The location of villages differs by position, and the method to form the conditions of location varies greatly. This study has comprehensively investigated village layout in the riverside and directional relations in houses. With changes in riverside landscape and transition to an agriculture-oriented village, there have been changes in road and the size, shape and direction of houses as well. In terms of the direction of houses situated along the river, a house facing the river accounts for more than half of all houses in the village. As traditional houses are transformed into modern houses over time, houses have become bigger, and the number of the houses facing south or southeast has been on the rise. As described above, riverside landscape and preference for the house facing south have an effect on determination of the facing direction of houses. However, the direction of geographical features of the village was first followed, and other conditions have been reflected, and the characteristics for the facing direction of houses have been observed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.68-71
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• 2006

Seasonal fluctuation of groundwater level by pumping amount and stream discharge at the riverbank filtrate site adjacent to the Nakdong River in Daesan-Myeon was characterized. Groundwater level fluctuation shows increase in wet season (June, July, August and September) and decrease in dry season (the other months). Seasonal variation of pumping amount shows similar trend to the groundwater fluctuation due to higher consumption of potable water in summer. The relation of specific capacity, Nakdong River and pumping quantity was analyzed. The logarithmic relationship between specific capacity and the stream discharge gives high correlation coefficient, 0.96. This fact indicates that the increase of stream discharge rate reduces the rate of drawdown in the pumping area in wet season.

• Proceedings of KOSOMES biannual meeting
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• 2001.10a
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• pp.137-144
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• 2001

A Plankton ecosystem model was developed to investigate effects of hydrodynamic processes including advection and diffusion on size-structured phytoplankton dynamics in the mesohaline zone of the York River estuarine system, Virginia, USA. The model included 12 state variables representing the distribution of carbon and nutrients in the surface mixed layer. Groupings of autotrophs and heterotrophs were based on cell site and ecological hierarchy Forcing functions included incident radiation, temperature, wind stress, mean How and tide which includes advective transport and turbulent mixing. The ecosystem model was developed in FORTRAN using differential equations that were solved using the 4th order Runge-Kutta technique. The model showed that microphytoplankton blooms during winter-spring resulted from a combination of vertical advection and diffusion of phytoplankton cells rather than in-situ production in the lower York River estuary.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.329-336
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• 1998

Sandmats are used to dissipate trapped water rapidly from the embankment built on marine soft ground. At present, however, it becomes difficult to obtain qualified sands since natural resources such as river sand are to exhausted. Also, low permeability of sand may cause low degree of consolidation and instability of embankment. In this study, design and construction methods was discussed. Drainage capacities of prefabricated horizontal drains which were installed in highway construction site are investigated in order to find possible substitution for river sands as drainage materials. On the basis of measurement data at the construction site, it was concluded that use of the prefabricated horizontal drains shows satisfactory drainage capacity without instability of embankment.

• Water Engineering Research
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• v.1 no.1
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• pp.25-37
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• 2000

This study presents some results of a preliminary study for the coupled precipitation and river flow prediction system. The model system in based on three numerical models, Mesoscale Atmospheric Simulation model for generating atmospheric variables. Soil-Plant-Snow model for computing interactions within soil-canopy-snow system as well as the energy and water exchange between the atmosphere and underlying surfaces, and TOPMODEL for simulating stream flow, subsurface flow, and water tabled depth in an watershed. The selected study area is the 2,703 $\alpha_4$ $\km_2$ Soyang River basin with outlet at Soyang dam site. In addition to providing the results of rainfall and stream flow predictions, some results of DEM and GIS application are presented. It is obvious that the accurate river flow predictions are highly dependant on the accurate predictation predictions.

• Journal of Environmental Science International
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• v.13 no.8
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• pp.739-746
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• 2004

Concentrations of PCBs in the sediment of the Kumho River was determined. Samples were collected at 23 locations along the river. Total PCB levels ranged from 2.7 to 87.6 ng/g dry weight. The site near the Keomdan factory district had the highest concentrations. The levels of PCB congeners significantly correlated with the total organic carbons in the sediment. The major fractions of PCBs were congeners containing 4, 5, or 6 chlorine atoms per biphenyl molecule.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.1
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• pp.103-109
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• 1990

The application of the Log-Pearson Type m distribution recommended by Water Resources Council, U. S. A. for flood frequency analysis requires the estimation of the regionalized skew coefficient. In this study, regionalized skew coefficients are estimated using a weighted regression model which relates at-site skews based on logarithms of observed annual flood peak series to both basin characteristics and precipitation data in the Han river and the Nakdong river basin. The model is developed with weighted least squares method in which the weights are determined by separating residual variance into that due to model error and due to sampling error. As the result of analysis, regionalized skews are estimated as - 0.732 and - 0.575 in the Han river and the Nakdong river basin, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.5
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• pp.108-118
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• 2003

There are plenty of ecological and traditional resources around Wandong and the Hwangryong-River district, and so the purpose of this development plan is to preserve ecological resources and traditional culture, and to utilize potential value of recreation in this site. Two major concepts are established in this plan one is “Green-Tourism”, the other is “Blue-Recreation”. In this development plan “Green-Tourism” means the effective tourism using ecological and traditional resources, while “Blue-Recreation” means the active tourism using waterfront and cultural facilities. The concept of “Green-Tourism” is applied to the Wangdong area, which is comprised of 6 theme zones. The concept of “Blue-Recreation” is applied to the Hwangryong-River area, which is composed of 4 theme zones. In total, 10 theme zones are planned according to characteristics found in the regional surroundings and cultural facilities of each zone.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1013-1022
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• 2005

Because depth of deposit is deeper as well as compressibility is very larger than the other regions in Korea, behaviour of settlement at Nak-Dong river estuarine causes hot issue at ground improvement. Defined properties for design differ from measurement. Therefore it affects cost of construction. This study presents design standard to engineers as it defined properties of compressibility at Jangyu Area of Nak-Dong river estuarine. To search value of representation for region, back analysis was performed using the measurement. To verify that, the measurement of recently designed site was confirmed, and the cost of construction with properties of consolidation was calculated.