• Title, Summary, Keyword: river water

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Optimum Water Allocation System Model in Keumho River Basin with Mathematical Programming Techniques (수리계획을 이용한 금호강유역의 최적 물배분 시스템모델)

  • 안승섭;이증석
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.2
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    • pp.74-85
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    • 1997
  • This study aims at the development of a mathematical approach for the optimal water allocation in the river basin where available water is not in sufficient. Its optimal allocation model is determined from the comparison and analysis of mathematical programming techniques such as transportation programming and dynamic programming models at its optimal allocation models. The water allocation system used in this study is designed to be the optimal water allocation which can satisfy the water deficit in each district through inter-basin water transfer between Kumho river basin which is a tributary catchment of Nakdong river basin, and the adjacent Hyungsan river basin, Milyang river basin and Nakdong upstream river basin. A general rule of water allocation is obtained for each district in the basins as the result of analysis of the optimal water allocation in the water allocation system. Also a comparison of the developed models proves that there is no big difference between the models Therefore transportation programming model indicates most adequate to the complex water allocation system in terms of its characteristics It can be seen, however, that dynamic programming model shows water allocation effect which produces greater net benefit more or less.

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Analysis of Sediment Discharge by Long-term Runoff in Nakdong River Watershed using SWAT Model (SWAT 모형을 이용한 낙동강 유역의 장기 유출에 따른 유사량 분석)

  • Ji, Un;Kim, Tae-Geun;Lee, Eun-Jeong;Ryoo, Kyong-Sik;Hwang, Man-Ha;Jang, Eun-Kyung
    • Journal of Environmental Science International
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    • v.23 no.4
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    • pp.723-735
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    • 2014
  • Sediment discharge by long-term runoff in the Nakdong River watershed should be predicted for the maintenance and management of the Nakdong River newly changed by the four major river restoration project. The data establishment by the analysis of runoff and sediment discharge using the long-term watershed model is necessary to predict possible problems by incoming sediments and to prepare countermeasures for the maintenance and management. Therefore, sediment discharges by long-term runoff in the main points of the Nakdong River were calculated using SWAT(soil and water assessment tool) model and the relations and features between rainfall, runoff, and sediment discharge were analyzed in this study. As a result of sediment discharge calculation in the main points of the Nakdong River and tributaries, the sediment discharge at the outlet of the Naesung Stream was greater than the Jindong Station in the Lower Nakdong River from 1999 to 2008 except the years with low precipitation. The sediment discharge at the Nakdong River Estuary Barrage (NREB) was corresponding to 20% of the Jindong Station which is located about 80 km upstream from NREB.

EFFECTS OF RIVER DISCHARGE ON GROWTH OF PERIPHYTON IN SAND RIVER

  • Toda Yuji;Tsujimoto Tetsuro;Fujimori Noriomi
    • Water Engineering Research
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    • v.6 no.3
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    • pp.113-122
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    • 2005
  • Periphyton is known to be one of major primary producers for river ecosystem. While the growth of periphyton usually observed on the stone surface in gravel river, the large growth of periphyton is sometimes seen even in sand river with relatively small river discharge. In the present study, field observations and numerical simulations were performed to investigate the growth of periphyton in sand river. In the field observation, the growth of periphyton on fixed sand bed was measured weekly. The results of the field observations show that the large growth of periphyton occurs in sand river until the bed material sands have not moved. An integrated numerical simulation model is presented to describe the growth of periphyton at observed river reach, and a series of numerical simulations were performed to study the effect of river discharge on growth of periphyton in the sand river. The results of the numerical simulations show that the net primary production of periphyton decreases with the river discharge. These results suggest that the reduction of river discharge at ordinary water stage strongly affects the primary productivity of periphyton even in sand river.

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A Study on the Improvement of RIMGIS for an Efficient River Information Service (효율적인 하천정보 서비스를 위한 RIMGIS 개선방안 연구)

  • Shin, Hyung-Jin;Chae, Hyo-Sok;Hwang, Eui-Ho;Lim, Kwang-Suop
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.1
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    • pp.15-25
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    • 2013
  • The RIMGIS(River Information Management GIS) has been developed since 2000 for public service and practical applications of related works after the standardization of national river data such as the river facility register report, river survey map, attached map, and etc. The RIMGIS has been improved in order to respond proactively to change in the information environment. Recently, Smart River-based river information services and related data have become so large as to be overwhelming, making necessary improvements in managing big data. In this study a plan was suggested both to respond to these changes in the information environment and to provide a future Smart River-based river information service by understanding the current state of RIMGIS, improving RIMGIS itself, redesigning the database, developing distribution, and integrating river information systems. Therefore, primary and foreign key, which can distinguish attribute information and entity linkages, were redefined to increase the usability of RIMGIS. Database construction of attribute information and entity relationship diagram have been newly redefined to redesign linkages among tables from the perspective of a river standard database. In addition, this study was undertaken to expand the current supplier-oriented operating system to a demand-oriented operating system by establishing an efficient management of river-related information and a utilization system capable of adapting to the changes of a river management paradigm.

Relations of Nutrient Concentrations on the Seasonality of Algal Community in the Nakdong River, Korea (낙동강 조류군집의 계절적 변화와 영양염 농도와의 관계)

  • Yu, Jae Jeong;Lee, Keung Lak;Lee, Hye Jin;Hwang, Jeong Wha;Lyu, Heuy Seong;Shin, La Young;Park, A Reum;Chen, Se Uk
    • Journal of Korean Society on Water Environment
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    • v.31 no.2
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    • pp.110-119
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    • 2015
  • The construction of the eight large weirs in the Nakdong River, the second largest river in Korea, caused big changes in the physical environment of the water system. Algal communities and their correlations with environmental factors, mainly nutrients were studied at five weir areas in the Nakdong River from 2010 to 2013. Water quality, hydrodynamics and algal composition were investigated. Results showed that flow velocities were reduced compared with that before weir construction near the areas where are located in the mid and upstreams of the Nakdong River. A seasonal algal community succession was observed and it was mainly correlated with temperature and phosphorus. Diatoms were dominated from winter to spring months and massive diatomic blooms of Stephanodiscus sp. occurred early in March during survey period. Cyanobacterial blooms of Microcystis sp. occurred from July to September 2013 and was preceded by the lower total phosphorus concentration of $0.05mg\;L^{-1}$. The correlations between total phosphorus concentrations and algal abundances were not significant during the survey periods. However, significant correlation with cyanobacteria was found in the period of weir construction after only at the GG survey site and blooms periods of 7 times in the survey sites, and its correlation coefficients were 0.53 (p<0.001) and 0.42 (p<0.01) respectively. When algal bloom was observed, partially low nutrient concentration was observed in the Nakdong River. In conclusion, partially low nutrient concentration which may result from algal bloom was observed, and we presume it caused the reduction of algal abundunces.

Surveying irrigation water withdrawls for river operation (하천운영을 위한 농업용수 취수량 조사)

  • 김현준
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.47-50
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    • 1999
  • From 1997 irrigation water withdraws has been surveyed for the purpose of river operation and management . Recently , the River Law was revised (1999.2.8) and obligate to water users to report their proposed and actual water withdrawals. If we can save more water from rice paddy area, we can use more water for municipal and industrial activity and we can expect water quality should be improved in the river. So the role of irrigation water use efficiency is more and more important.

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Evaluation of the tributaries by influence index on the mid-lower portion of the Nakdong River basin

  • Lee, Shun-Hwa;Jung, Seung-Gyu;Park, Seoung-Muk;Lee, Byung-Dae
    • Environmental Engineering Research
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    • v.23 no.2
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    • pp.150-158
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    • 2018
  • The deteriorating role of Nakdong River due to the Four Major Rivers Project has caused a series of problems, including water pollution, drying streams, aggravation of the hydroecology. Geumho River and Gyeongseong-cheon had a higher concentration index and is believed to impact the water quality of the main stream. The influence index of Geumho River and Nam River between 2015 and 2016, which have a large amount of discharge, was the highest among the tributaries in terms of the load material balance. Showing the highest average concentration and average load in the index assessment, Geumho River is believed to require an intensive management for improving the water quality of the main stream. Furthermore, when the cumulative percentage of the average concentration and average load was compared based on the water quality improvement of the tributaries mixed to Nakdong River, which was set to 60%, Geumho River, Nam River, Topyeong-cheon, and Cha-cheon, which showed the highest ratio in that order, were determined to require a water quality management program as a priority.

Water Quality Assesment of the Lower Yeongsan River System (영산강 하류권역 하천수의 수질평가)

  • Youn, Seok-Tai;Koh, Yeong-Koo;Oh, Kang-Ho;Moon, Byoung-Chan;Kim, Hai-Gyoung
    • Journal of Environmental Impact Assessment
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    • v.12 no.4
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    • pp.259-270
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    • 2003
  • To investigate the water quality and the pollution state of lower Yeongsan river system, 38 water samples were taken from the main stream of the Yeongsan river, Gomakwon and Hampyeong streams of the system in dry and flood seasons, May and August, 2001. The Yeongsan river is typically natural in accordance with pH-& diagram. But the chemistry based on Piper's diagram indicates that the river is influenced by seawater. BOD increases as the sampling sites are approaching the downstream in Gomakwon and Hampyeong streams overwhelming WQS V grade of 12.40mg/l. T-N and T-P of the river are mainly loaded not in above branch streams but in the main stream of the river, which are caused by manure for farming, domestic animal discharges and life-sewage, in possible. Meanwhile, heavy metal contents are below WQS or not detect in whole water samples. So, it shows that the above river waters be polluted by not industrial but life/agricultural foul waters.

Verification of Water Environment Network Representative at the Baekcheon Junction of the Nakdong River (낙동강 백천 합류부 지점의 물환경측정망 대표성 검증)

  • Ahn, Jung Min;Im, Teo Hyo;Kim, Sung Min;Kim, Shin;Kim, Gyeong Hoon;Kwon, Heon Gak;Shin, Dongseok;Yang, Deuk Seok
    • Journal of Environmental Science International
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    • v.27 no.6
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    • pp.371-381
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    • 2018
  • Multifunctional weirs constructed through the Four Major Rivers Restoration Project are operated as management water levels. The purpose of this study was to evaluate the effect of water level in the main stem on the tributary water level according to multifunctional weir operation, because the operation of multifunctional weirs for water level management influences the drainage of tributaries. In this study, water level pressure gauges were installed and spatial and temporal water quality was observed. The LOcally Weighted Scatterplot Smoothing (LOWESS) technique was applied to the Nakdong River and the Baekcheon Junction, both upstream of the Gangjeong-Goryeong weir, in order to analyze water quality trends. When considering the overall analysis and observations, it was found that the water quality forecasting point located at the Baekcheon estuary point should be transferred to the Dosung Bridge, which is located upstream of the Sunwon Bridge.