• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.2
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• pp.95-104
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• 2010

The purpose of this study is to analyze the correlation between physical stream characteristics and bed materials in natural rivers. Accordingly, four natural rivers were selected reference streams, they were Nam river, Sumjin River, Naesung River and Han River. Grain size distributions of bed materials were gravels, cobbles and boulders in Han river and Nam river, were sand, gravels, cobbles and boulders in Sumjin river and were sand in Naesung river. Four reference streams were divided into each two reference reaches (straight and bend) by plan and profile characteristics of naturally meandering stream. Therefore various reference reaches were chosen in the aspect of physical stream characteristics and grain size distributions. The results investigated and analyzed are as follows. The streams that grain sizes distributions of river bed materials were coarse were stable because they had variety of bed slope without sediment deposition, and then the riffles frequency and the physical characteristics were various. Also, velocitydepth regime were various in four kinds, and the response parts for water level change were small, so that channel flow status were stable and excellent condition. On the other hand, sand river that grain sizes distributions of river bed materials were fine had not the variety of parameters as velocity-depth regimes, sediment deposition, channel flow status and riffles frequency, so that the physical stream characteristics were not various.

• Journal of Wetlands Research
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• v.9 no.3
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• pp.51-61
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• 2007

In natural river, river-bed change is greatly influenced by the various factors such as river improvement, change of watershed land use, construction of dam and reservoir, gravel mining, and so on. The knowledge about river-bed change in the river is essential in the river modification, wetlands plan, and maintaining stable alluvial rivers. In this study, river-bed change in the future was predicted by investigating river channel characteristics which play dominant role in the formation of channel and based on the numerical model through river survey and the grain size analysis. The Proposed investigation and model was applied to the Geum river and the Miho stream which have been experienced river degradation due to river aggregate dredging and now seams to be stable. The result of potential river-bed change which was estimated by investigating channel characteristic including slope of channel, friction velocity, and so on is similar to that which was estimated based on the numerical model. It was found that the Geum river and the Miho stream will be stable. In the future, if considering the characteristics of river channel which is estimated by the river-bed scour, sediment, and so on, it is possible that river improvement and wetland restoration plan are established stably and naturally.

• Journal of Korean Port Research
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• v.14 no.1
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• pp.107-114
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• 2000

Derivation of stage-discharge relationship and characteristics for Yangsan river is presented in this paper. This research has been conducted as the second one after the first trial in 1997. The determination of discharge at a Yangsan river gauging was best made by measuring the flow velocities with a current meter and rod float. The rating curve obtained through 52 stage-discharge measurements on Yangsan river basin in 1999 is represented by Q=15.3540-140.6076H+182.44372H$^2$, which is discovered to be most excellent among other curves in reliability analysis. The observed stage-discharge data for Yangsan river was tested by HEC-RAS program, and reproduction of discharge by the induced curve was investigated and compared with the computational results. The rating curve of Yangsan river shows characteristics of Yangsan river more accurately compared with those separated in terms of water levels.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.41-46
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• 1998

The purpose of the study was changed of Flood Characteristics in Down stream of Keum River by the Keum River Estuary Dam Construction. The water surface slope of Kuem river after the Keum River Estuary Dam construction was steeper then before. The flood control capacity increase after construction. But, Increasing sediment in Kuem river will be decreased flesh reservoir volume for yield irrigation.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.71-80
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• 2009

Due to the various characteristics of urban river, rehabilitation project for natural river requires distinct alternative approach and selection method for each different types of river. In this study, naturalness of a river was used to establish such alternative for the business and rehabilitation plan for natural river. To assess the naturalness of a river, through AHP, designed to fit the environmental conditions in Korea, was employed. Furthermore, a method that conveniently compares and selects an alternative for rehabilitation plan for natural river by referencing Urban River Basin Enhancement Methods (URBEM) was proposed. After selecting the evaluation items for assessing the naturalness of the river based on the characteristics of the river, multiple alternatives were constructed and the naturalness of river for each of those alternatives were estimated. Comparing the estimated values has made the measurement of the natural recovery effect and the product of river rehabilitation plan for each alternative efficient. In conclusion, selecting the items for evaluating the naturalness of a river with respect to its characteristics was found to be effective for establishing the rehabilitation plan for natural river.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.59-64
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• 1998

The characteristics of agricultural water rights in multi-purpose dams in Korea was examined. The river system with multi-purpose dams can be divided into national river system and WRC(Water Resources Corporation) river system according to ownership of dam use rights. While the national river system have permitted water rights, the WRC river system have vest water rights and contract water rights. The two river systems have different characteristics of agricultural water rights, and therefore the water right of two system need to be unified. It is also known that water release from multi-purpose dams against water demand does not satisfy agricultural water rights.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.6
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• pp.152-161
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• 2006

This study is the primary study for analyzing the classifying characteristics of river wetlands in Korea and China. It is the first step for constructing the wetlands inventories and establishing the wetland conservation strategies in North-Eastern Asia. The case study sites are Han-river which is the representative river of Korea and Tu-men river which is flowing on the borderline of 3 nations, China, North Korea and Russia. The results are as follows : 1. The types of wetlands of Han-river in Korea and Tumen-river in China were classified by the methods of Koo(2002) which is focused on the topography and hydrology and Zhu(2002) which is emphasized the vegetation and habitats. 2. There are three features which are hydrology, topography and soil cover, and vegetation to classify the wetlands into each types. 3. According to the two wetland types by Koo and Zhu, classification system, wetlands in the case study area(Han river and Duman river) were classified by types. 4. In Koo's classifying system(2002), lots of Riverine, Lacustrins and Flat wetlands are found because the topographical and hydrological features are emphasized. On the contrary in Zhu's system(2002), there are lots of Palustrine wetlands because of emphasizing the vegetation. 5. By the topographic and geological characteristics of each sites, there are more wetland types in the lower Tumen river.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.3
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• pp.479-486
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• 2012

Runoff characteristics of pollutant loads of the lower Han River was studied before full implementation of Total Pollution Load Management System(TPLMS). Magnitude of macroscopic(annual) fluctuation was in the order of Namhan River > Han River > Bukhan River, gross weight TP > gross weight TN > gross weight BOD, gross weight deviation > concentration deviation. Flux variation was higher than that of concentration. Microscopic(weekly) fluctuation showed similar pattern to macroscopic scale. TP showed the highest deviation resulting in the lowest reliability. 60% of annual flux passed during summer 3months resulting in 43-46% pass of gross weight at the lower Han River. Strong correlation was found between flux and gross weight especially in gross weight TN. Gross weight pollution increased as high as 400% while passing Seoul area due to the concentration. The deviation from moving average increased during summer season in the gross weight TP and BOD. Seasonal tendency was confirmed especially in gross weight TN and TP using autocorrelation function.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1732-1736
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• 2008

The characteristics of a river flow analysis are significant for river maintenance plan. At the present time, HEC-RAS, 1-Dimensional Numerical Analysis Model, is mainly applied to analyze the character of a river flow. The shape of a river is somewhat in longitudinal linear form. It was suspected that the usage of 1-dimensional numerical analysis model is more economical. Development of numerical analysis models and computers are possible to calculate large volume. Hence, it is possible to adapt the analysis of the key stations by 2-dimensional numerical analysis model. The limitation of 1-Dimensional Numerical Analysis Model is that it is hard to evaluate structure affection of numerical simulation by energy loss coefficient at river structure analyzing. When adaptation of the 2-dimensional numerical analysis model in river structure ensues, it takes more objective analyzing than 1-dimensional numerical analysis model for flow affection by river structure. 2-dimensional numerical analysis model consults with the different structure position of hydraulic characteristics and different water depth of shape and scope in vertical flow. 1-dimensional numerical analysis model is possible to simulate with only energy loss coefficient for sudden river section changing, sudden waterway changing by curved. 2-dimensional numerical analysis model use original geographical features. So the model removes technical subjectivity of faulty judgment. It is an objective analysis.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.6
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• pp.61-70
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• 2002

This study was performed to analyze the river fractal characteristics using GIS (Geographic Information System). In this study, topographical factors in river basin were grid-analyzed for each cell size and scale using GIS and regression formula was derived by analyzing correlation among topographical factors and cell size which were calculated here. And, a new rainfall-runoff model which is considering the calculated fractal dimension was developed to apply fur a river basin.