• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.673-683
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• 2016

An Idea to estimate flexible criteria for river water use permits was proposed that takes the spatio-temporal flow variation along the river into account, which was applied to the Keumho River, one of the tributary of the Nakdong River in Korea. This idea implies the temporal division of four periods with different criteria, combining flood/non-flood seasons and irrigation/non-irrigation periods, while a single one has been applied throughout the year in the current practice. Through flow regime analysis of daily natural flow simulations at Dongchon and Seongseo, the control points of the study area, Q355 and 1Q10 for non-flood and non-irrigation period, Q275 for non-flood and irrigation period, Q185 for flood and irrigation period were suggested respectively. So, those values that subtract instream flow were determined as the flexible criteria in each season. From the comparison of current practice and the proposed method, it was estimated that $10.6\;million\;m^3/year$ is available for more water use permits without additional development of water storage. Therefore, it is conceived that flexible criteria for river water use permission suggested in this study can contribute to improve the national policies for more efficient water resources management in the future.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.540-545
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• 2006

The objective of the study is to assess the water quality improvement resulted from the rearrangement of the irrigation water supply systems at Mankyeong River and Ansung Chun basin. There is a mixed type of watershed composed of urban and rural areas in the region. The water intake facilities for agricultural use such as reservoir, weir and pumping station are generally located at upstream river where the water quality maintains relatively clean. However, this study focuses on moving the water intake to downstream and rearranging the irrigation water supply system, then investigating how effective they are for water quality improvement in the river. When the water intake is moved downstream, the stream flow is increased as much as the amount of irrigation water that is to be taken upstream. The augmented flow which is frequently referred to as environmental flow can function as dilution water for improving the quality of polluted water that is originated from the wastewater in tributaries.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.471-474
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• 2003

An attempt was made to evaluate on water supply capability of river management flow of four agricultural dam at the Yongsan River which is required instream flow because of water pollution. As a result, supply capability of agricultural use was sufficient, but supply capability of river management flow was insufficient.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.84-94
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• 1998

The sources of the pollution on a river are divided into two classes, one the point source and the other non-point source. In raining, especially, the non-point source discharged from paddy, residential area, road ${\cdots}$ etc have correlations with the land use. This study was carried out to find out the model to estimate the quality of water in a river according to the land use. Land use data (Pungse-Myeoun and Kwangduk-Myeoun in Chonan) were produced from Landsat TM (Thematic Mapper) and topographic map. Total nitrogen(TN) and total phosphorus(TP) general indices for the degree of pollution in river were measured during 11 months. Correlations between two variables(Land use and Pollutants(TN, TP)) were explained by the regression coefficient. As a result of this study, we found that among the five types of land use, the residential area, store area and paddy have significant effects upon the quality of water in a river. The results of this study will be applied to pre-estimate the degree of pollution in river broadly and to offer basic data in establishing the land use plan and the concept on the conservation of the river in rural area.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.53-57
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• 2007

Tsurumi River Basin successfully started to prepare a Water Master Plan though a series of discussions by gathering all stakeholders in a hall. It began with setting five management targets namely, flood, low flow, natural environment, emergency use, and recreational use, followed by setting management goals by target as well as a one-sentence catchphrase for the Water Master Plan using a bottom-up approach. The author reviews this process and discusses the background of the success.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.198-198
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• 2016

The Citarum River Basin is the biggest river basin in West Java Province, Indonesia and it plays strategic roles in providing water for irrigation, domestic and industrial uses, and power generation, besides controlling the flood during rainy season. Flowing through seven major cities makes the river flow and water demand are vulnerable to land use change around the river. The present water resources management has involved the regulator, operator, and users in deciding an appropriate water management plan for the entire basin. The plan includes an operation plan for three reservoirs, construction or maintenance of the river channel, and water allocation for all users along the river. Following this plan, a smaller operation group will execute and evaluates the plan based on the actual flow condition. Recently, a deforestation, environment degradation, river sedimentation, a rapid growth of population and industry, also public health become new issues that should be considered in water basin planning. Facing these arising issues, a new development program named ICWRMIP was established to advance the existing management system. This program includes actions to strengthen institutional collaboration, do the restoration and conservation of the river environment, improve water quality and public health, also advance the water allocation system. At present, the water allocation plan is created annually based on a forecasted flow data and water usage prediction report. Sometimes this method causes a difficulty for the operator when the actual flow condition is not the same as the prediction. Improving existing system, a lot of water allocation studies, including a development of the database and water allocation simulation model have been placed to help stakeholders decide the suitable planning schemes. In the future, this study also tries to contribute in advancing water allocation planning by creating an optimization model which ease stakeholders discover a suitable water allocation plan for individual users.

• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.975-984
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• 2019

As an essential prerequisite for systematic and integrated management of river water, it is necessary to secure the basic data such as discharge supplied to the river and released from the river. Under the current permit system for river water use, 59.1% of licensed facilities were found to have no discharge meters in 2017, especially for agricultural water, which makes it difficult to secure reliable data as a large portion of the reports are voluntarily reported by users. In this study, the indirect discharge measurement method of calculating the discharge through the power usage of the pumping station was applied to secure reliable discharge data. In particular, focusing on the fact that the discharge calculated by the power usage method differed with the actual discharge according to the level of the river, the study was conducted on improving the power usage method reflecting the river water level and improving the accuracy of discharge data. Analysis of the discharge calculated using the power usage method considering river water level using the correlation analysis method such as regression analysis, percent difference, root mean square error etc. confirmed that the results are not high compared to the conventional power usage method, but are slightly more approximated to the actual discharge. Therefore, although reliable discharge data can be obtained from the existing power usage method, it is expected that more accurate data on intaking water of river water can be obtained if the improved power usage method is used at points where the variation in the water level of the river is large.

• Hwankyungkyoyuk
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• v.24 no.1
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• pp.40-48
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• 2011

SimRiver, computer simulation software for assessment of river water quality is an educational simulation software created for studying the relationship between human activity and river environment using epilithic diatom communities, The SimRiver program was applied to total seventy eight teachers of elementary, middle and high schools in Korea, and the teachers' reactions were analyzed with the questionnaire survey. Total 79.2% of the teachers estimated the possibility of SimRiver to be applied as a educational material in lessons is high. Especially total 93.6% of the teachers answered that they will use SimRiver in their lessons. The results of the questionnaire survey indicate that SimRiver is an interesting and easy simulator of alternative field exercise for students to understand the relationship between human activity and quality of river water.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.147-147
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• 2018

In this article, we use an open source software library: TensorFlow, developed for the purposes of conducting very complex machine learning and deep neural network applications. However, the system is general enough to be applicable in a wide variety of other domains as well. The proposed model based on a deep neural network model, LSTM (Long Short-Term Memory) to predict the river water level at Okcheon Station of the Guem River without utilization of rainfall - forecast information. For LSTM modeling, the input data is hourly water level data for 15 years from 2002 to 2016 at 4 stations includes 3 upstream stations (Sutong, Hotan, and Songcheon) and the forecasting-target station (Okcheon). The data are subdivided into three purposes: a training data set, a testing data set and a validation data set. The model was formulated to predict Okcheon Station water level for many cases from 3 hours to 12 hours of lead time. Although the model does not require many input data such as climate, geography, land-use for rainfall-runoff simulation, the prediction is very stable and reliable up to 9 hours of lead time with the Nash - Sutcliffe efficiency (NSE) is higher than 0.90 and the root mean square error (RMSE) is lower than 12cm. The result indicated that the method is able to produce the river water level time series and be applicable to the practical flood forecasting instead of hydrologic modeling approaches.

• Journal of Korea Water Resources Association
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• v.46 no.10
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• pp.1017-1028
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• 2013

The purpose of this research is to develop an Integrated Water Resources Evaluation Index (IWREI) which can used to assess the performance of water resources projects in a regional perspective focusing on three major sectors including water use, flood, and river environment in water resources policies. The IWREI is estimated by integrating the Water Use Vulnerability Index (WUVI), the Flood Vulnerability Index (FVI), and the River Environment Vulnerability Index (REVI) which represent the vulnerability in each sector. These indices consist of total 26 indicators selected from the pressure indicators representing the causes of damages in water use, flood, and river environment, the state indicators and the response indicators. The estimated index describes the vulnerability and effectiveness of policies with five levels: Low, Medium Low, Medium, Medium High, and High. The results of evaluating total 115 hydrological units in Korea using the WUVI, FVI, REVI, and IWREI indicate that the project effectiveness in water resources policies is clearly verified by the improved index results compared to the past (early 1990s). Regional vulnerability and evaluation indices developed in this research could be used to establish goals of water resources policy and to select priority regions for project implementation.