• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1425-1434
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• 2021

Continuous and periodic data acquisition must be preceded to maintain and manage the river facilities effectively. Adapting the existing general facilities methods, which include river surveying methods such as terrestrial laser scanners, total stations, and Global Navigation Satellite System (GNSS), has limitation in terms of its costs, manpower, and times to acquire spatial information since the river facilities are distributed across the wide and long area. On the other hand, the Mobile Mapping System (MMS) has comparative advantage in acquiring the data of river facilities since it constructs three-dimensional spatial information while moving. By using the MMS, 184,646,009 points could be attained for Anyang stream with a length of 4 kilometers only in 20 minutes. Levee points were divided at intervals of 10 meters so that about 378 levee cross sections were generated. In addition, the waterside maximum and average slope could be automatically calculated by separating slope plane form levee point cloud, and the accuracy of RMSE was confirmed by comparing with manually calculated slope. The reference slope was calculated manually by plotting point cloud of levee slope plane and selecting two points that use location information when calculating the slope. Also, as a result of comparing the water side slope with slope standard in basic river plan for Anyang stream, it is confirmed that inspecting the river facilities with the MMS point cloud is highly recommended than the existing river survey.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.5
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• pp.97-110
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• 2018

The purpose of this study is to provide basic data and evidence for the habitat improvement of wild birds in urban stream by analyzing changes in habitat characteristics of wild birds by riparian forest construction in Yangjae stream in Seoul. In Gangnam-gu, the multi layered riparian forest consisting of landscape trees and shrubs was formed on the slope. In Seocho-gu, the vertical vegetation structure of woody and herbaceous wetland plants was good. In Gangnam-gu, the vegetation area of the slope increased and the vertical stratification structure affected the species diversity of the forest birds. The number of species and individuals of plovers, sandpipers and wagtails decreased due to the impact of bicycle roads and trails. The poor forests on the levee slope in Seocho-gu affected the habitat selection and migration of the forest birds. The willows and amur silver-grasses formed in the riverside have been developed into the riparian forest, thus stabilizing the habitat of water birds by blocking disturbances from the influence of the trails.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.133-148
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• 2014

In order to investigate community formation ability, herbaceous perennials such as Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka were planted in April 2009 at the levee slope of Gwangju Stream in South Korea. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. which grew in pots for two years and divided rhizomes of Arundinella hirta Tanaka gathered from fields were employed. Weeds growing on the experiment sites were removed twice a year until 2011 when the plant species were formed into community. Weeds were not eradicated during 2012 and 2013 to observe community sustainability of the species. T-tests on stem numbers and heights in May, July and September were conducted between 2011 and 2012, and between 2012 and 2013. Stem numbers of the five species in 2012 were significantly reduced(p<0.001) compared with those in 2011, which were attributed to weed growth in 2012. Heights of Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka in 2012 were significantly lower than those in 2011(p<0.001), which resulted from weed invasion. Heights of Miscanthus sacchariflorus Bentham in May and July 2012 were significantly decreased compared with those in 2011(p<0.001), however, heights of Miscanthus sacchariflorus Bentham in September 2012 were almost the same as those in 2011(p>0.05). Miscanthus sacchariflorus Bentham was able to compete against weeds in September 2012. Stem numbers and heights of Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. in 2013 were similar to those in 2012(p>0.05). However, stem numbers and heights of Arundinella hirta Tanaka in 2013 were significantly decreased compared with those in 2012(p<0.001). After community formation, Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. were able to maintain its community without weed removal. However, Arundinella hirta Tanaka was unable to establish its community due to the weed growth. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne are more suitable to stream levee slope environment in terms of community formation and maintenance, stream landscape enhancement and slope erosion control.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.99-104
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• 2015

Topsoil including numerous soil seedbanks has been known to be a valuable material for ecological restoration. There is a lack of specific study for its utilization in the field of stream restoration. This study conducted a revaluation of the value of topsoil as a material for stream restoration. Furthermore, an ecological technique using topsoil was applied in an improvement project of a stream environment at the Hwanggujicheon Stream in Korea. Stockpiling and spreading topsoil was specifically applied to the revegetation of a low slope revetment and a high flow plain. The result of this application showed that topsoil played an integral role in eco-friendly restoration in terms of ecological, flood control, economic, and constructional aspects. In conclusion, this study's findings suggest that topsoil is a suitable candidate material for stream restoration.

• Journal of the Korean association of regional geographers
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• v.13 no.4
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• pp.409-421
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• 2007

The purpose of this paper is to consider the formation processes and depositional conditions of bars formed at the upper-stream part of Sayeon Dam since Sayeon Dam construction in 1964. Results of analyzing the shape characteristics of bars and their sediment grain size distribution are as follow: Firstly, bars are able to categorized as subaqueous bars (A, B), mid-channel bars(C, D), and tributary side-bars(E). Secondly, the outline of bars has longish along the flow path, and their height lowers more and more going towards downstream. Also the height of bar surface tend to heighten from flow path to mountain slope. However, the near part of A is comparatively higher than its distant part, A is defined as a subaqueous natural levee and back swamp. Thirdly, the average particle size of A and B become smaller toward mountain slope. In transportation style, ratio of suspended load become higher toward mountain slope. Fourthly, sorting is worse to very worse according with lake's random changable water level. Fifthly, bar A and B were formed by vertical sedimentation of sediments according as sediments transported along flow path in the subaqueous conditions were spreaded out of flow path. C and D were formed by bed load as flood level lowered. And E was formed by vertical sedimentation while stream flow stopped in tributary's mouth areas with the water level heightening.

• Journal of Korea Water Resources Association
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• v.49 no.11
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• pp.931-939
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• 2016

Bangudae Petroglopys of the national treasure No. 285 located in elevation of 53 m to 57 m have been damaged by repetition of submergence and exposure due to the Sayeon-dam of EL.60 m constructed in down stream. In this study, as a preservation plan of the petroglyphs from the contact with water, the construction of eco-levee was suggested and its effect was investigated in the views of hydraulic engineering. It was designed to be located aside of 80 m from Bangudae Petroglyphs with the length of 440 m in streamwise direction, and it was need to construct a new channel maintaining the original hydraulic capacity and conveyance. Hydraulic characteristics such as water surface elevations and velocities near Bangudae Petroglyphs were measured after the eco-levee was installed in the hydraulic model with the scale of 1:50. It showed that there were not much changes of water surface elevations and velocities between sayeon-dam spillway EL. 60 m (Suggestion 1) and EL. 54 m (Suggestion 2). It was concluded the eco-levee could be made of natural materials like soil, pebble, gravel in terms of allowable velocity and shear stresses. The slope of water surface at Suggestion 2 was steeper, and velocities near Bangudae Petroglyphs were also faster than Suggestion 1. As the vorties occured at the left side in Suggestion 2, more detailed study is required.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.2
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• pp.49-55
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• 1982

The purpose of this study is to classify the factors influenced on the damages of head works suffered from the storm flood occurred on July 22 1980 in both Musim and Bochong rivers and to find out an integral counter measures against the causes influenced on the disaster of head works in the engineering aspect of planning, design, construction and maintenance. In this survey, number of samples was taken 25 head Works, and the counter measures against the causes of their disasters summarized was as follows, 1. In the aspect of planning a. As the flood water level after the establishment of head works is more increased than the level before setting of head works owing to having more gentle slope of river bed between the head works than nature slope of river bed. Number of head works should be reduced for the appropriate annexation of them b. In the place where head works is established on the curved point of levee, the destruction of levee becomes severe by the strong deflective current. Therefore the setting of head works on the curved point should be kept off as long as possible and in case of unavoidable circumstances the construction method such as reinforced concrete wall or stone wall filed with concrete and anchored bank revetments should be considered. 2. In the aspect of design a. As scoring phenomena at up stream is serious around the weir Where the concentration of strong current is present in such a place, up stream apron having impermeability should be designed to resist and prevent scoring. b. As the length of apron and protected bed is too short to prevent scoring as down stream bed, the design length should be taken somewhat more than the calculated value, but in the case the calculated length becomes too long to be profitable, a device of water cushion should be considered. c. The structure of protected river bed should be improved to make stone mesh bags fixed to apron and to have vinyl mattress laid on river bed together with the improvement for increasing the stability of stone mesh bags and preventing the sucked sand from the river bed. d. As the shortage of cut-off length, especialy in case of the cutoffs conneting both shore sides of river makes the cause of destruction of embankment and weir body, the culculation of cut-off length should be taken enough length based on seepage length. 3. In the aspect of design and constructions a. The overturing destruction of weir by piping action was based on the jet water through cracks at the construction and expansion joints. therefore the expansion joint should be designed and constructed with the insertion of water proof plate and asphalt filling, and the construction joint, with concaved shape structure and steel reinforcement. b. As the wrong design and construction of the weep holes on apron will cause water piping and weir destruction, the design and construction of filter based on the rule of filter should be kept for weep holes. c. The wrong design and construction of bank revetment caused the severe destruction of levee and weir body resulting from scoring and impulse by strong current and formation of water route behind the revetment. Therefore bank revetment should be designod and constructed with stone wall filled with concrete and anchored, or reinforced concrete wall to prevent the formation of water flow route behind the wall and to resist against the scoring and impulse of strong stream. 4. In the aspect of maintenance When the damaged parts occurred at head works the authorities and farmers concerned should find and mend them as soon as possible with mutual cooperation, and on the other hand public citizen should be guided for good use of public property.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.1083-1095
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• 2003

The analysis of drying stream characteristics for about 500 streams from field survey data with 19 items has been fulfilled. Also, a study area has been determined, and criteria of estimation has been established : criteria such as, available hydrological data, the size of stream lengths and basin areas and regional characteristics. Then they are applied to designated study areas. The final selected study areas are 8 basins. The analysis of drying stream characteristics using a GIS has been applied to 5 basins in which spacial data is comparatively implemented among the final 8 target catchments. The spacial analysis using a GIS is applied to stream slopes for upstream and downstram at weirs, overlaying the map of buffering stream networks and ground water pump stations map, sinuosity of drying stream. As a result of drying streams survey analysis, drying stream characteristics are followed; levee types are earth and natural, cross sectional shapes are trapezoid, stream bed materials are gravels and sands, facilities in streams are weirs. As a result of GIS analysis, stream slopes are comparatively larger downstream than upstream close to weirs. There are arranged ground water pump stations less than 500m from stream networks. Also the average of sinuosity for each drying stream is in the range of 1.229∼1.475, comparatively a serious.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.21-37
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• 2010

The abiotic factors and the vegetation naturalness of the 13 tributary wetlands around Namgang-River were assessed to investigate the present state and to present the conservation counter plan for the wetland ecosystem of the tributaries. Assessment indices for the abiotic factors were estimated based on the dominant land use types of the riparian zone, ecological function of the upper levee, levee slope structure, artificiality and utilization intensity of the waterfront, artificiality of the revetment structure, diversity of the substrate, and severance of the transverse. The assessment index of Omi-cheon is the highest among 13 tributaries. The second was Banseong-cheon and third was Hyangyang-cheon, followed by Nabul-cheon and Yeongcheon-gang and Sugok-cheon, Jungchon- cheon, and Daegok-cheon in their order and Munsan-cheon got the lowest assessment index. Assessment indices for the vegetation naturalness were estimated based on the vegetation diversity, exotic species dominance, annual herb dominance, naturalness and peculiarity of the vegetation, and species diversity. The assessment index of Omi-cheon is the highest among 13 tributaries. The second was Sugok-cheon and third was Banseong-cheon, followed by Yeongcheon-gang, Jungchon- cheon, Jinae-cheon, Nabul-cheon, and Jisu-cheon in their order, and Yonga-cheon got the lowest assessment index. The grades of the stream naturalness were estimated based on the the naturalness indices for the abiotic factors and the vegetation naturalness. The grades of Omi-cheon is the highest among 13 tributaries as the grade I. Those of Banseong-cheon, Sugok-cheon, Yeongcheon-gang, Nabul-cheon and Jungchon-cheon, Hyangyang-cheon, Jinae-cheon, Jisu-cheon, Daegok-cheone, and Munsan-cheon and Doksan-cheon were grade II in their order, and Yonga-cheon got the lowest as the grade III. It was suggested that restoration of the simple and flat substrate, create the natural vegetation on the levee slope constructed with concrete or stone wall, and rehabilitation of the eco-bridge were demanded to improve the grades of the stream naturalness through the restoration of the tributaries for the diverse aquatic wildlife, high vegetation diversity and species diversity with the vegetation consisted of perennial herbs and trees.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.23-43
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• 2020

The purpose of this paper is to create ecological values for urban rivers. For this, the paper looks into river bed structures and how nearby lands are used. This study was performed to set the specific sections for analysis through a field investigation of the infrastructure conditions, surrounding land use, and the inter habitat structure of Seongnaecheon(Stream). A total of 780 individuals from 31 species of wild birds appeared in Seongnaecheon(Stream). According to foraging guild's habitat, there were 9 species of water, 8 types of water edges, 5 types of crowns, 5 types of shrubs, 2 types of tree trunks, 2 types of birds of raptors, and 355 individuals of water, 243 shrubs, 90 crowns, 84 water edges and 5 raptors. Many water birds were observed at the site where the Seongnaecheon(Stream) sandy plains and wetland herbaceous area were developed and the open water was secured. Most of the forest birds appeared on levee slope connected with forest around and riverside with fewer facilities for use. The species diversity index of Shannon, the entire section of Seongnaecheon(Stream), was 2.2697 and the downstream ecological landscape conservation area of Seongnaecheon(Stream) was found to be useful as a habitat for wild birds in the city compared to other sections. Some sections of Seongnaecheon (Stream) had low species diversity index due to lack of green space and surrounding urbanization areas. In choosing target species, I researched the special features of the habitats and the habitation structure of wild birds in each zone. Regarding detailed plans, by classifying the breeding place & roosting site and the roosting site & shelter that took account of the inhabitation characteristics of the target species in different sections, this paper suggested the major plant species and multilayer planting structures. Moreover, this study proposed the development of habitats for water birds and forest birds along with the connection of the green network for improving the Eco-corridor linkage and inhabitation features in Seongnaecheon(Stream).