• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.734-738
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• 1999

This study is to modify the EUTRO5(sub-model of WASP5) for applying river water quality simulation. Because previous version of EUTRO5 has unique kinetic constant for all segement on each constituent, EUTRO5 is not adequate for some river simulation. As this version have each kinetic constant for all segment on each constituent, it will be suitable for model application with rapid changing geometry and kinetic purification of upstream river.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1996.10a
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• pp.64-71
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• 1996

현재 3분의 2정도가 농업지역이며 27%는 삼림지 그리고 도시 등의 개발지역이 약 6%를 차지하고 있는 대부분의 미개발지역으로 구성된 미국 동부 지역에 대서양과 접해있는 메릴랜드 연안만이 최근들어 Ocean City라는 도시를 중심으로 급속한 산업발전을 하고 있어 그로 인한 도시생활하수 등 하ㆍ폐수의 증가로 부영양화가 우려되고 있다. (중략)

• Journal of Environmental Impact Assessment
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• v.8 no.1
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• pp.93-105
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• 1999

Lately water quality of Daechong Reservoir has become more eutrophicated than ever before and there has been much concern over especially the eutrophication of the embayment near Daejon and Chongju Water Intake Tower every summer. The purpose of this study is to predict the impact of change in the pollutant loading, flowrate, nitrogen and phosphorus release from sediment, SOD(sediment oxygen demand) upon the water quality of Daechong Reservoir by WASP5/EUTR05 in order to suggest water quality management alternatives. The data of Sep. 1995 were used for the calibration of the model and those of Sep. 1997 was for verification. The result of the modeling can be summarized as follows. 1. The 50% increase(decrease) of pollutant loading has caused that of T-N concentration by 0.10-0.14 mg/l, T-P concentration by 0.003-0.005 mg/l, and CBOD concentration by 0.16-0.18 mg/l. But the ratio of DO change by the change of pollutant loading was relatively small. 2. The sensitivity test of NH4 flux to T-N and that of P04 flux to T-P shows that T-N and T-P concentration were changed more in the epilimnion segments (SEG4, SEG5, SEG6, SEG7) than the other segments. As SOD increases, DO was predicted to decrease more especially in the hypolimnion (SEG9-SEG14). 3. As flowrate increase, the concentration of T-N, T-P, and CBOD were predicted to decrease, but DO concentration increased especially in the hypolimnion segments(SEG11, SEG12, SEG13, and SEG14). As the flowrate changed from $119m^3/sec$ to $50m^3/sec$, the concentration of T-N and CBOD in the hypolimnion was predicted to decrease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1465-1472
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• 2011

Water quality surveys has been performed to establish water quality improvement strategy for the lake Pyeungtaek, and WASP model was used to simulate to identify the effect of water quality improvement according to the reduction of pollutant loadings for the upstream watersheds. Assuming that present loadings was continued up to the future, the water quality of the lake was found to be getting worse resulting from the increase of pollutants due to the planned future development. In this study, we made various scenarios to predict the future water quality, scenario 6 made a large contribution to improve the lake water quality compared to others. Even the scenario 6, COD concentration of year 2016 in the lake was examined to be under the 4th rate of water quality level for the lake (COD less than 8 mg/L), similar to year 2021. Even though additional reduction of loadings for the scenario 6 was made, the water quality in lake was a little improvement, and was though to be inappropriate action in the economic point of view.

• Journal of Korea Water Resources Association
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• v.33 no.2
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• pp.145-157
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• 2000

The Water Quality Analysis Simulation Program 5 (WASP5) and HEC-2 models have been coupled and applied to find the possibility of simulation of long-term river water quality variation. The EUTR05 as a simulator of water quality simulation in WASPS model was used to simulate the water quality variables in the downstream of Geum-River from Daechung multi-purpose dam during the dry period. The water quality and flow rate conditions have been measured at the stage measurement stations located in the downstream of Geum-River from Daechung dam in December, 1998 and January and March, 1999. The water quality simulation model was calibrated with January data of 1999, and verified with December data of 1998 and March data of 1999. The trend of longitudinal variation of water quality variables simulated by model is consistent with that of measured water quality constituents except chlorophyll-a, $BOD_5,\;NH_3-N\;and\;PO_4-P$ simulated with March data of 1999. Furthennore, the chlorophyll a concentration in the mainstream of Geum-River was simulated by changing the concentrations of $PO_4-P$ and/or $NH_4-N$ flowing into the mainstream of Geum-River from Gabcheon and Mihocheon. The variation of chlorophyll a concentration in the mainstream was almost ignorable except only when $NH_3-N\;and\;PO_4-P$ concentrations decreased by 70% flow into the mainstream from Gabcheon and Mihocheon.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6567-6574
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• 2015

In order to estimate the characteristics of the growth and composition of phytoplankton according to the available nutrients, we added nitrate (0, 1, 5, 10, 20, 50, $100{\mu}M$) and phosphate (0, 0.1, 0.5, 1, 2, 5, $10{\mu}M$) to field samples in a eutrophic site (St. 1) and an oligotrophic site (St. 22) in 2010 as well as a eutrophic site (St. 1, 5), a mesotrophic site (St. 19), and an oligotrophic site (St. 22) in 2011 at Jinhae Bay, Korea. The phytoplankton growth in the areas with additional nitrates and phosphates on St. 1 were significantly different from the control (One-way ANOVA:P<0.01). The dominant species at St. 1 in 2010 were Heterocapsa triquetra and Pseudo-nitzchia spp., to which nitrate and phosphate were added, respectively. The dominant species at St. 22 in 2010 differed between treatment conditions as follows: nitrate treatment Chaetoceros spp. (${\leq}10{\mu}M$), Thalassiosira spp. ($20{\mu}M$), and Pseudo-nitzchia spp.(${\geq}50{\mu}M$) for nitrate treatment; Cylindrotheca spp. ($2{\mu}M$) and Pseudo-nitzchia spp. ($5{\mu}M$) for phosphate treatment. Phytoplankton growth in 2011 according to the added nutrient were significantly different with treatment concentrations (One-way ANOVA: P<0.01). Moreover, the beginning of exponential growth in phytoplanktons was different between the eutro-mesotrophic sites (St. 1, 5, and 19) and the oligotrophic sites (St. 22) on day 2 and day 6 respectively. This implies that phytoplankton growth in the low nutrient condition may be retarded. The dominant species at St. 1 were Eucampia spp. and Chaetoceros spp. in the low nutrient treatment compared to Skeletonema spp., and Thalassiosira spp in the high nutrient treatment. The dominant species at St. 5 and St. 19 were mostly Skeletonema spp. and Chaetoceros spp. However, the dominant species at St. 22 was Thalassiosira spp.. The results of this study showed that phytoplankton growth and composition were different in areas with different nutrient characteristics resulting from the additional nutrients. Therefore, the nutrients additional algal assay could be indirectly explained why the biomass and composition of phytoplankton in Jinhae Bay has shown spatial differences.