• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2B
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• pp.145-152
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• 2006

In the present study, a nonlinear model of rainfall-runoff process using Artficial Neural networks(ANNs) which have no consideration on the physical parameter for the basin was developed at Naju station which is the main stream of Yeongsan-river, and Sunam station which is the main stream of Hwangryong-river. The result from the model of ANN_NJ_9 at the Naju station revealed the best result of the rainfall-runoff process, while the model of ANN_SA_9 for the Sunam station. Also, GUI_FFS developed in the research showed the $R^2$ of more than 0.98 between the observed and predicted values using the rainfall and runoff in the respective stations. Therefore, the GUI_FFS might be expected that it can play a role for the high reliability to operate and manage the water resources and the design of river plan more efficiently in the future.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.480-480
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• 2022

4대강 살리기 사업 중 영산강 살리기 사업의 일환으로 건설된 보의 영향을 파악하기 위해 수질에 대해 통계분석과 통합수질지수를 이용한 수질변화 분석 및 경향성을 파악하여 합리적인 수질관리를 위한 기초 자료를 제공하고자 하였다. 이를 위해 영산강 본류의 3개 지점, 20년간 자료를 이용하여 보 건설 전·후로 구분하여 수질변화와 통합수질지수를 산정하고 경향성을 분석하였다. 통합수질지수 경년별 평가는 3개 지점 모두 보 건설 후에 수질이 다소 개선되는 것으로 나타났으며, 광산지점의 수질등급은 대부분 불량으로 거의 변화가 없었다. 영산포지점의 수질등급은 보 건설 전 주의~불량에서 보 건설 후 대부분 주의로 개선되었다. 무안2지점의 수질등급은 보 건설전 양호~주의에서 보 건설 후에는 양호로 개선되었다. 통합수질지수 월별평가는 3개 지점 모두 보 건설 후 전반적으로 수질이 개선되었으며, 광산지점의 수질등급은 보 건설 전보다 악화되었다. 영산포지점의 수질등급은 전반적으로 개선되었다. 무안 2지점의 수질등급은 대부분 보통 및 주의에서 보 건설 후에 우수 및 양호로 변화되었다. 통합수질지수 경향성 분석은 보 건설 후 영산포 지점을 제외하고 모두 증가 경향을 나타냈고, 전반적으로 수질이 개선되고 있는 것으로 판단된다. 본 연구는 영산강 4대강 사업의 일환으로 건설 된 보로 인한 수질변화를 수질항목에 대하여 분석하고 통합수질지수를 산정하여 평가하였다. 전반적으로 BOD, T-N, T-P는 수질이 개선되었고, COD 및 Chl-a는 수질이 악화되었으나, 총인고도처리시설 설치와 총질소 처리효율 개선등의 영향으로 보의 영향을 정확히 파악하는데 한계가 있었으나, 영산강 수질관리를 위한 기초자료로서 활용될 것이라 기대된다.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.903-916
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• 2023

This study aims to establish basic data for efficient management of rural water by analyzing regional irrigation facilities and benefitted areas in the statistical yearbook of land and water development for agriculture at the watershed level. For 511 domestic rural water use areas, water storage facilities (reservoirs, pumping & drainage stations, intake weirs, infiltration galleries, and tube wells) are spatially distributed, and the benefitted areas provided at the city/county level are divided by water use area to provide agricultural water supply facilities. The characteristics of rural water district areas such as benefitted area, were analyzed by basin. The average area of Korea's 511 rural water districts is 19,638 ha. The average benefitted area by rural water district is 1,270 ha, with the Geum River basin at 2,220 ha and the Yeongsan River basin at 1,868 ha, which is larger than the overall average. The Han River basin at 807 ha, the Nakdong River basin at 1,121 ha, and the Seomjing River basin at 938 ha are smaller than the overall average. The results of this basic analysis are expected to be used to set the direction of various supply and demand management projects that take into account the rational and scientific use and distribution of rural water and the characteristics of water use areas by presenting a quantitative definition of Korea's agricultural water districts.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.248-252
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• 2012

To evaluate the possibility of water plant wastes in composting for agricultural recycling, Phragmites communis (PHRCO), Typha orientalis (TYHOR) and Zizania latifolia (ZIZLA) were used as a compost materials. In composting basin, cumulative oxygen consumptions of the compost used by water plant wastes were rapidly increased at the early stage and slightly decreased in around 15 days. Cumulative oxygen consumptions under different water plant wastes were higher in the order of TYHOR > ZIZLA > PHRCO. Temperature changes during composting process were rapidly increased at the early stage and then slowly decreased to $30{\sim}40^{\circ}C$. The maximum temperatures were higher in the order of ZIZLA ($72.2^{\circ}C$ at 11 days after starting composting) > TYHOR ($70.2^{\circ}C$ at 10 days after starting composting) > PHRCO ($66.5^{\circ}C$ at 7 days after starting composting). Oxygen consumptions at maximum temperature were higher in the order of TYHOR ($12,485mg\;O_2\;kg^{-1}$) > ZIZLA ($12,400mg\;O_2\;kg^{-1}$) > PHRCO ($9,340mg\;O_2\;kg^{-1}$). Organic matter contents, moisture contents and OM/N rates in the compost ranged 39.5~44.8%, 29.6~35.6% and 27.9~32.9, respectively. Considering that water plant waste can supply some of the nutrient requirements of crops and is a valuable fertilizer.

• Analytical Science and Technology
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• v.28 no.6
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• pp.377-384
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• 2015

A survey of the artificial radionuclides in rivers and lakes was conducted to investigate their levels in surface water. Water samples were collected at 60 points and analyzed by gamma-ray spectrometry with a measurement time of 10,000 seconds for ¹³⁴Cs, ¹³⁷Cs, and ¹³¹I. The obained values were lower than MDA for all points, except one point for ¹³¹I that was 0.533±0.058 Bq/L. ¹³¹I is known as a radioactive material that occurs frequently in sewage treatment plants. Because it is often used for medical treatments and subject to spreading into the environment due to the excretion from the patients. For the point where ¹³¹I was detected, we conducted additional investigation on the upstream river point and the effluent points of nearby sewage treatment plant to find the source of ¹³¹I. ¹³¹I was not detected at the upstream points of one of the upstream sewage treatment plants but found at the downstream points with the level being 0.257±0.034 to 0.799±0.051 Bq/L, proving the sewage treatment plant was the ¹³¹Isource.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.9-16
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• 2013

BACKGROUND: Eutrophication occurs occasionally in reservoirs around lake in summer and early autumn. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during rainy season. To improve water quality of water supply source in Boknae reservoir around Juam lake, characteristics of nutrient(N, P) uptake and release by submerged plants were investigated. METHODS AND RESULTS: In order to establish the management plan of submerged plants in Boknae reservoir around Juam lake, water level, rainfall, flooding and non-flooding areas, biomass of dominant plants, contents of nitrogen and phosphorus were investigated during 7 months(August, 2010 through February, 2011). Dominant plants were Miscanthus sacchariflorus(MISSA) and Carex dimorpholepis(CRXDM) in Boknae reservoir. Total plant area of Boknae reservoir in August, 2010 was 987,872 $m^2$. In Boknae reservoir, flooding occurred from August until February caused by rainfall during rainy season. The total amounts of nitrogen and phosphorus uptakes by MISSA were 247 and 22 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus uptakes were 11,340 and 1,231 kg/total reservoir area, respectively. The total amounts of nitrogen and phosphorus residues by MISSA were 34 and 11 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus residues were 491 and 68 kg/total reservoir area, respectively. CONCLUSION(S): Total amounts of nitrogen and phosphorus releases in Boknae reservoir were 12,212 and 1,324 kg/total reservoir area, respectively. The results demonstrate that total nitrogen and total phosphorus in water were strongly influenced by submerged plants. Therefore, management plan for submerged plants during rainy season will be needed to improve water quality of water supply source in Boknae reservoir around Juam lake.

• 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.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.258-265
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• 2009

To develop environmentally friendly constructed wetlands(CWs) for treating domestic sewage which was produced in farming and fishing village, the efficiency of water treatment at different ventilation systems in the vertical bed, depths of horizontal bed, and sewage loads was investigated. In the vertical bed, BOD and COD by duplex ventilation system were lower than those by single ventilation system. But T-N and T-P concentrations by both ventilation systems in the vertical bed were little different. In the horizontal bed, BOD, COD, T-N and T-P in 1.0 m and 1.3 m depths were little different. To reduce the CWs' area and to improve the pollutant removal efficiencies, the optimum depth of horizontal bed was 1.3 m. In single and duplex ventilation CWs, the removal rate of BOD, COD, SS, T-N and T-P decreased slightly with the sewage load increases. In same sewage load conditions, the removal rates of BOD, COD, SS, T-N and T-P by duplex ventilation CWs were higher than those by single ventilation CWs. In summary, to effectively treat domestic sewage from farming and fishing village, the optimum constructed wetlands would be the duplex ventilation CWs.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.373-381
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• 2008

To select of optimum rice species and germanium (Ge) application method for production of functional rice with Ge, the growth characteristics, Ge absorption and grain quality of rice plant were investigated under different rice species (Hopyungbyeo, Junambyeo, Ilmeebyeo and Dongjinbyeo) and Ge application method (soil application and foliar spray). The rice yield by soil application was higher in the order of Hopyungbyeo $\fallingdotseq$ Junambyeo > Ilmeebyeo >> Dongjinbyeo. On the other hand, the rice yield by foliar spray was higher in the order of Junambyeo >> Ilmeebyeo > Dongjinbyeo > Hopyungbyeo. The rice yield by soil application was higher than that by foliar spray regardless of rice species. For soil application, the Ge absorption in various parts of the rice was higher in the other of rice bran > brown rice > polished rice regardless of rice species. The Ge absorption of brown rice in Hopyungbyeo, Ilmeebyeo, Dongjinbyeo and Junambyeo by soil application was 14.5, 8.0, 11.6 and $10.4\;mg\;kg^{-1}$, respectively. In leaf, stem and root, the Ge absorption by foliar spray was higher than that by soil application, whereas, in rice bran, brown rice and polished rice, the Ge absorption by soil application was higher than that by foliar spray. The optimum rice species and Ge application method were demonstrated to be Hopyungbyeo and soil application, respectively, which provided suitable conditions for production of functional rice with Ge.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.197-206
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• 2007

This study was conducted to survey the population of water birds wintering at the seven coastal wetlands of Jeollanam province including Suncheon Bay and Yeongsan Lake, from 2000 through 2003. The 90 species and 857,570 individuals in total were sighted at the seven survey sites. We classified the wintering water birds into seventeen groups of taxa based on the similar ecological attributes, among which, eight groups were found to inhabit the water surface or riparian areas. Classified groups that showed higher rate of using bay areas than that of lake areas were in the order of waders, gulls and swans. On the other hand, the groups that showed higher rate of using lake areas than that of using bay areas were revealed in the order of dabbling ducks, grebes and geese. In conclusion, there was a difference in the pattern between the two classified groups. As a result of the UPGMA cluster analysis using CCs ($S{\varnothing}rensen'a$ index of similarity and Ro (Horn's index of community overlap), the results showed that Suncheon Bay had the most unique species formation out of the seven areas. Bay and lake areas were different from each other in the formation of species and Individuals. As a result of combining the index rank according to the maximum aggregate count, the Suncheon Bay is ranked the highest in importance of the habitats for water birds, followed by the order of Boseong-Deukryang Bay, Gangjin Bay, Gocehongam Lake, Geumho Lake, Yeomam Lake, and Yeongsan Lake. Considered overall, the importance of the bay areas was relatively higher than that of reclaimed lake areas.