• 한국생태학회:학술대회논문집
• /
• 2002.08a
• /
• pp.113-118
• /
• 2002

Vegetation and riverine structures were compared among urban and several semi-natural rivers by applying direct gradient analysis and ordination method. Urban rivers showed different species composition from the semi-natural ones. Species composition of semi-natural rivers depended on the geographical positions, such as the upstream, midstream, and downstream and on micro-topographies, such as the waterside, flooding bed, and embankment. Semi-natural rivers showed gentle change in micro-topography, whereas urban one did not so. Our restoration plan to improve the ecological quality of the degraded urban river by imitating semi-natural river was prepared based on those data.

• The Korean Journal of Ecology
• /
• v.25 no.4
• /
• pp.247-252
• /
• 2002

Vegetation and riverine structures were compared among urban and several semi-natural rivers by applying direct gradient analysis and ordination method. Urban rivers showed different species composition from the semi-natural ones. Species composition of semi-natural rivers depended on the geographical positions, such as the upstream, midstream, and downstream and on micro-topographies, such as the waterside, flooding bed, and embankment. Semi-natural rivers showed gentle change in micro-topography, whereas urban one did not so. Our restoration plan to improve the ecological quality of the degraded urban river by imitating semi-natural river was prepared based on those data.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.446-446
• /
• 2018

The urban rivers have unique hydraulic characteristics between natural rivers and artificial canals. These hydraulic characteristics determine the characteristics of urban rivers with small environmental capacity and fragile ecosystems. With the development and utilization of natural resources, the pollutants that have been produced enter the river through different channels, which seriously damages the urban river ecosystem. Therefore, how to restore contaminated water to a normal state and reproduce a natural, self-regulating ecosystem is one of the most concerned issues in recently. Eco-hydraulics is a cross-disciplinary subject of hydraulics biology and ecology. It is closely related to the protection of rivers, wetlands, and ecological self-repair. In this study, The basic principle of eco-hydraulics is concisely described and its approaches to protection and rehabilitation of river are introduced. The conception of establishing gardenesque eco-pond for urban use is suggested. The strategies including changing the hydrodynamic features of rivers, adjusting the breeds and species and constructing the gardenesque eco-pond for improving the exist ing urban rivers are proposed. It provides scientific information and guidance for the restoration of rivers and wetlands by studying the close relationship between river hydraulic characteristics, currents, and rivers and ecosystems.

• Proceedings of the Korea Contents Association Conference
• /
• 2006.05a
• /
• pp.322-326
• /
• 2006

There are the road of the artificial government property and rivers of the natural government property in representative Public Facilities applied National Reimbursement Law. Art.5. Doctrine on Responsibility of Public Facilities. Recently damage of a people has frequently been occurring caused by the flood of rivers and the flood disaster, and a people tends to request national reimbursement regarded it not as a natural disaster but as a man-made disaster. Especially the flood repeatedly occurred by the flood of rivers and destructive of the embankment of rivers, and it is also occurring in repairing rivers. Therefore a nation have to take responsibility of compensation for damage because of defect of conservation of rivers, and pay attention to improving the facilities of conservation and at the same time expand the range of responsibility. Thus the range of this study limits the national reimbursement of conservation of rivers among National Reimbursement Law. Art.5. Compensation for Damages on Defect about an Establishment and Management of public Facilities. Within this range, the objection of this study is to seek controversial issues and solutions, which belong with national reimbursement responsibility about conservation of rivers, as every principle of law and precedent coming under natural government property about compensation for damages caused by defect of conservation of rivers is analyzed and examined.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.9 no.4
• /
• pp.1-12
• /
• 2006

The usages of urban riverine areas for the Gapchoen and Yudungcheon in Daejoen City were evaluated by analyzing riverbed characteristics and water quality and by surveying the status of the floodplain usage including questionnaires of people visiting the rivers. Both rivers appear to be stable with insignificant bed changes as the riverbeds are dominated by gravels. Water qualities of both rivers have been improved significantly over the past decade although there are quite large seasonal fluctuations, which is common in most rivers in Korea. The results of floodplain usage analyses show that Gapcheon is dominated with static uses (>70%) such as promenades and resting facilities, while Yudungcheon by dynamic uses (>44%) such as sports facilities. Overall, both rivers require better plans for riverine area usage management considering a balance between the dynamic uses and the static uses such as natural observation places for education and habitats for birds and fish in the rivers. The questionnaire survey results indicate that overall the present status of both rivers are satisfactory and that water quality improvement is one of the key factors to enhance the value of the riverine areas. Future river restoration should be conducted by taking into account the characteristics of urban rivers in harmony with surrounding natural sceneries.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.3
• /
• pp.128-142
• /
• 2009

A lot of efforts have been made to resolve balancing problems between flux and source term and most finite volume models under development have been applied to simple channels such as imaginary and experimental channels. However, a number of numerical problems which can not be found in simple channels occur in the application to natural rivers and the problems should be resolved to apply finite volume models to natural rivers. In this study, 2D finite volume model which is applicable to natural rivers was developed and the accuracy of the developed model was validated through the application of partial dam break In addition, a simple and efficient 2D mesh generation method was suggested and the method can be accurately reflected to 2D mesh converted from surveyed cross sections in Han-river using GIS. The accuracy and applicability of the developed model on natural rivers were verified by performing simulation on Han-river using the generated mesh and comparing computed water elevation with measured water elevation.

• Geosciences Journal
• /
• v.22 no.6
• /
• pp.989-1000
• /
• 2018

The provenance of the Central Yellow Sea Mud (CYSM) in the Yellow Sea has been attracted a great deal of attention over the last three decades, but a consensus is not yet reached. In this study, 101 surface sediment samples collected from the CYSM were investigated to determine provenance and transport mechanisms in the area using the clay minerals and major element components. The Huanghe sediments are characterized by higher smectite, but the Changjiang sediments are more abundant illite contents. Western Korean rivers contain more kaolinite and chlorite than do Chinese rivers. The Chinese rivers have higher $Fe_2O_3$, MgO, and CaO than the Korean rivers at the same $Al_2O_3$ concentration. Therefore, the clay minerals and major element concentrations can be useful indicator for the source. Based on our results, we suggest that the surface sediments in CYSM were composed mainly of Changjiang sediments, mixed a partly with sediments from the Huanghe and the western Korean rivers. Although the northwestern part of CYSM is proximate to the Huanghe, the contents of smectite and CaO were extremely low. It could be evidence that the Huanghe materials do not enter directly into the CYSM due to the Shandong Peninsula Front. Considering the oceanic circulation in the Yellow Sea, the Changjiang sediments could be transported eastward with the Changjiang Diluted Water and then mixed in CYSM via the Yellow Sea Warm Current (YSWC). Huanghe sediments could be provided by coastal currents (Shandong Coastal Current and Yellow Sea Coastal Current) and the YSWC. In addition, sediments from western Korean rivers might be supplied into the CYSM deposit via the Korean Coastal Current, Transversal Current, and YSWC.

• The Journal of the Korea Contents Association
• /
• v.12 no.7
• /
• pp.445-452
• /
• 2012

This study is used to analyze the distribution of resistance factors and the relationships of flow resistance with the field measurements which consist of the total 2,604 rivers for 1,865 bed material in natural channels and 739 vegetation in vegetated channels. Resistance factor relationships and distribution range of Manning roughness coefficients and Darcy-Weisbach friction coefficients by the regression analysis are derived from the power law form as a function of flow discharge and friction slope with bed materials and vegetations in natural and vegetated rivers, respectively.

• Ecology and Resilient Infrastructure
• /
• v.1 no.2
• /
• pp.82-93
• /
• 2014

In recent years, "ecological river restoration" taking into account the flood control, water utilization and environmental aspects of rivers is actively being investigated. However, it is hard to understand the inhabitation conditions of living organisms that live on the river with distinct characteristics have been fully reflected, and with the use of limited methods, it ends in uniformed composition of artificial rivers and a mere customary stream channel maintenance, resulting in frequently disturbed stream channel habitats As a fundamental study for investigating the habitats of living organisms that live on rivers, this study intends to examine each habitat type by dividing domestic rivers into sand rivers and gravel rivers depending on the nature of rivers and dividing sections of each river into central river sections and natural river sections. As a result, more diverse habitat types of organisms were found in the gravel rivers rather than in the sand rivers, and the habitat types of organisms in the central river sections where the river restoration project have been already conducted reached approximately 56.3 % of those that appeared in the natural river sections.

• Journal of Korea Water Resources Association
• /
• v.38 no.5 s.154
• /
• pp.333-343
• /
• 2005

The upwind model is well known to simulate shockwaves, but it is rarely applied to natural rivers because of problems caused by the source terms. Although several methods have been developed to deal with the source terms, none of them has been applied to natural rivers. This paper deals with application of the upwind model to the natural river. An implicit upwind model is applied to a hypothetical irregular channel and a natural river with highly irregular bed, width, and hydraulic structures. Different types of the flows including steady-state flow, flood wave, dam-break wave, and bore are simulated to test accuracy and applicability of the implicit upwind model. It is proved that the model can simulate various types of flows in natural rivers with high accuracy and robustness.