• Water for future
• /
• v.14 no.1
• /
• pp.39-49
• /
• 1981

The purpose of this study is to examine the meander charactericstics for the rivers in Korea..In this study, the new characteristics factors of meander are proposed, and the relationships among the factors proposed in this study and the existing factors are derived. An attempt is made to find considerable relation among meander characteristics, but width and meander belt did not show any defined trend and considerable scatter of points was observed. Relationships among the meander length, belt and flowrate, etc., which are factors of meander characteristics, are analyzed the 67 rivers above 30km in length. Channel shape factor which is the ratio of the length from the starting point to the end to the channel lenght, tortuosity which is the ratio of the curved channel length against the channel length are suggested for a new characteristics factor of meander. They are well correlated with channel length, Horton's shape facotr and meander gradient, consequently have to be important measures of river meander. The result of the detailed comparison and the analysis of degree of sinuosity, velocity and water surface slop are brought light on the fact show that the curved reach is morestable than the straight one. The ratio of the meander length to the meander belt and its accumulative frequency showed excellent correlationship when plotted on the semi-log paper. The results of regression analysis of meander belt and meander length show linear for the South Han river branches and power curve for the Geum river and the Nakdong river branches.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.13 no.6
• /
• pp.133-144
• /
• 2010

The objective of this planning proposal is to rehabilitate the urban stream which has been ecologically disturbed in the urban process. The experimental stream, Su-am stream located in Anyang City is typical urban stream in adjacent land use and the spatial condition. The stream in the watershed context, is the second tributary of Han River, in the Anyangcheon watershed. The Characteristics of the stream reach were analyzed by the river corridor survey. In the conceptual phase, Rehabilitation Programs were established based on the hydrological, ecological and spatial characteristics of the stream. Spatial zoning concept according to the characteristics of the stream and adjacent land use, was suggested 4 types of zoning; ecological preservation zone, natural landscape zone, neighborhood water-friendly zone and CBD water-friendly zone. Implementation Practices can be summarized as follow: For The longitudinal river continuum, some In-stream practices were suggested and implemented; such as channel alignment, step & pool, pool & riffle and low-flow channel bank. For latitudinal continuum and intimate spatial relationship between Sam-duk Park & Su-am stream, gentle sloped bank was planned and implemented. After stream improvement & ecological Implementation, follow-up monitoring and adaptive management programs will be a meaningful process for ecological rehabilitation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.2
• /
• pp.1441-1449
• /
• 2015

At the bends of a river, the deflected flow of high energy erodes the embankment and transports sediment, ultimately changing the river's course. Such phenomena lead to instability of the embankment and may cause serious problems for nearby roads, land, or riverside structures. This study intends to analyze the characteristics of hydraulic flow at S-shaped bends after the installation of Riprap Weirs designed to prevent changes in a river's course and embankment erosion. An experimental channel was constructed by a two-dimensional CCHE2D model, and analyzed the characteristics of hydraulic flow with and without the Riprap Weirs. Also, the characteristics of hydraulic flow at the inner and outer sides of river bends and at points near reservoirs were analyzed, depending on the intervals between the Riprap Weirs.

• Journal of Korea Water Resources Association
• /
• v.48 no.3
• /
• pp.169-183
• /
• 2015

As a basic work for river restoration, analysis on fluvial geomorphological characteristics is made using past and present data to understand close-to-nature geomorphic status. The Miho and the Naesung Rivers are targets of this study. Fluvial geomorphic variables including valley-floor width, sinuosity, bankfull width, channel gradient, bed material size, bankfull discharge and unit stream power are evaluated with dominant processes. Though common sand-bed rivers with similar catchment area, the Miho and the Naesung Rivers are different in terms of valley-floor width, channel shape variables and dominant processes related with longitudinal location. In addition, analyses on interrelationship among the geomorphological variables are carried. Bankfull width is shown to be proportional to bankfull discharge, as is in a rough agreement with the previous studies. Relationship of bankfull discharge and channel gradient shows meandering and braiding are prevalent in the Miho River, whereas the most of the sub-reaches of the Naesung River fall to braiding. Relationship of channel gradient with width-depth ratio indicates dune-ripple processes are dominant in the Miho River, while the Naesung River shows longitudinal diversity from braiding in the downstream sub-reaches to riffle-pool and plane-bed along the upper ones. Analyses based on the past data on a river in a close-to-nature status are thought to be rather reasonable in comparison with those on the same river in a engineered condition.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.10 no.3
• /
• pp.71-87
• /
• 2007

In order to improve and manage rationally for Youngdam creek in Haman-gun, the channel change, water quality and ecological adaptation etc. were evaluated by monitoring during three years. The distinct differences of channel characteristics appeared in the extents of bed excavation and the revetment methods because overall reconstruction was occurred intense disturbance of width expansion and levee construction etc. The scour and deposition were caused according to channel characteristics of ripple and pool, and the adaptation of vegetation was distinguished from each revetment methods clearly. Water quality was maintained first class on the basis of BOD as 0.5~1.5mg/${\ell}$. The vegetation appeared in 380 species close-to-nature river improvement before, but 64 species it after one year, 159 species it after two year and 158 species it after three year. The animal life appeared in 123 species of close-to-nature river improvement before, but 103 species it after one year, 116 species it after two year and 119 species it after three year.

• Ecology and Resilient Infrastructure
• /
• v.3 no.4
• /
• pp.285-293
• /
• 2016

This study conducted the evaluations of stable channel and physical disturbance improvement for optimal construction of river structures by focusing on Wonju River. A stable slope was analyzed sectionally for stable channel design, and in order to satisfy the stable slope, river structure improvement scenarios were deduced. Accordingly, through physical disturbance improvement evaluation for each scenario, the study extracted the optimal scenario for stable channel design and physical disturbance improvements. The changes in physical habitat were analyzed when river structure improvements were made for stable channel design and physical disturbance improvement. Zacco koreanus, an indicator fish of the soundness of the aquatic ecosystem, was selected as a restoration target species by investigating the community characteristics of fish fauna and river environments in the Wonju River. The habitat suitability was investigated by the PHABSIM model with the habitat suitability index of Zacco koreanus. The results of the prediction evaluation showed a slight decrease in habitat suitability and weighted usable area. However, it was not influenced by the improvements in the river structure. The study suggested river structure arrangement methods that can improve physical soundness and safety of Wonju River, and confirmed that there were no effects to the changes in the physical habitat.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2003.05b
• /
• pp.931-934
• /
• 2003

• Journal of the Korean Society of Hazard Mitigation
• /
• v.7 no.1 s.24
• /
• pp.47-56
• /
• 2007

The parameters are determined analyzing the hydraulic and hydrological characteristics of design floods, watershed, channel length, and river bed slope. The models are calibrated while the input hydrologic data are the field data of middle size areas in Guem river basin in Korea. The basic equations of design width are suggested by the multiple regression analysis and the results show excelled in comparisons as well as calibrations with the existing empirical formulas and the design criteria, respectively. The basic equations of design width in validation process is determined the regression functions with the design floods, watershed, channel length, river bed slope as the four parameters using other database in the same scales watershed. As a results, this study will be used for apply to determine of design width and river alignmentof the watershed in hydraulic fields.

• Water for future
• /
• v.15 no.1
• /
• pp.33-42
• /
• 1982

In recent years owing to extensive land reclamation, increased river engineering activites and morer intense flood plain use, river geomorphology has attracted considerable attention. One of outstanding problems has been maintenance of river meanders and nearly all natural river exhibit the tendency to meander. Often the meander geometry was fitted in to various idealized model. COnsequently, both the selection of data and the methods to determine the geometric parameters were highly subject to individual preferences. This study applied statistical analysis in tipifying their shape and analysised meander characteristics by channel model of line generalization algorithm. This method is applied to Geum river system. The results show that the variance of curvature is a better index to describe the meander intensity and the kurtosis is a good index to characterize the total length of the straight sections for a given reach. The results also show that channel model of line generalization algorithm is a good model in analysis of meander characterisitics.

• Water for future
• /
• v.13 no.2
• /
• pp.49-54
• /
• 1980

Meandering has been attributed to the earth's rotation, to the excessive slope and energy of a river, to changes in stage, etc. The purpose of this study is a geometrical approach of meander shape and to derive the relationship among meander characteristics. In the analysis of sime field examples, in spite of variety of meander shapes, the sine-generated curve was fit actual quite well and better than alternatives against the channel distance. An attempt is made to find considerable relation among meander characteristics. But width and meanderbelt did not show any defined trend considerable scatter of points was observed.