• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2078-2082
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• 2009

Riparian vegetation distribution patterns and diversity relative to various fluvial geomorphic channel patterns, stream bank stabilization methods, and stream flow processes are described and interpreted for selected stream of Goesan, Central Korea. Idong Stream Pilot Project, which began in May 2003 and finished in December 2003, was selected to develop effective methods. The project aim to maintain or increase stream bank stabilization ecosystem goods and services while protecting downstream and stream bank ecosystem. A number of protecting methods which are a Flight of fieldstone, Vegetation block, Green river block, Stone net, Green environment block, Eco friendly cobble, Vegetation mat and Geo green cell and Firefly block were applied on the bank of Idong stream. The stream sites have been monitored about flora conditions each method in 2007. We selected 12 points for summer seasons to separately investigate in left bank, right bank and river bed. The main purpose of this study was to find out suitable methods and to improve stream restoration techniques for ecosystem. On the stream bank, Eco friendly cobble method(9.57) was the highest average of vegetation cover and Firefly block method(3.87) was the lowest average in applied methods.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.2
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• pp.57-75
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• 2012

This study was carried out to investigate the flora of estuary regions, Namdaecheon, Jusucheon, and Maeupcheon, placed in the east coast of Gangwon-do. The vascular plants were summarized as 441taxa, including 90 families, 277 genera, 388 species, 2 subspecies, 35 varieties, and 6 forms. Number of species in each investigated region was 271taxa of Namdaecheon, 247taxa of Jusucheon, and 285taxa of Maeupcheon, respectively. Among the investigated 441taxa, 7 Korean endemic, 5 rare plants and 37 specially designated plants by Ministry of Environment were also included. Aquatic and hydrophyte plants were collected 41taxa, and the thinophyte and halophyte plants were investigated 22taxa. The naturalized plants were 59taxa, and the percent of naturalized plant species was estimated as 13.3%. Based on the floristic composition, Maeupcheon was estimated as well conserved estuary region among the investigated 3 rivers.

• Korean Journal of Ecology and Environment
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• v.42 no.4
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• pp.495-501
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• 2009

The study was conducted in 2007~2008 in order to understand preference of physical microhabitat on the $1^{st}$-class endangered species, Gobiobotia naktongensis inhabiting the Gam Stream, tributary of Nakdong River. The total number of fish caught from the study sites was 3,671 representing 7 families 24 species. There were 8 Korean endemic species including Odontobutis platycephala, and 2 introduced species (Carassius cuvieri, Micropterus salmoides) were found. According to investigation and analysis of physical microhabitat on Gobiobotia naktongensis caught in the Gam Stream, a total of 57 individuals were found at shallow depth (0.14~0.46 m) and run (0.239~0.585m $sec^{-1}$). As a result of sieve analysis, stream beds consisted of about 1% gravel and 99% sand (83.4% coarse sand, 15.6% find sand). Therefore, Gobiobotia naktongensis seemed to inhabit shallow-run with coarse sand bed than deep-pool microhabitat. The findings indicate preference of physical microhabitat on Gobiobotia naktongensis, and it is important to enhance efficiency of fish conservation and ecological restoration with understanding species-specific characteristics in microhabitat including protected species.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.97-110
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• 2021

Vegetation index information is an important figure that is used in many fields such as landscape architecture, urban planning, and environment. Vegetation may vary slightly in vegetation vitality depending on photosynthesis and chlorophyll content. In this study, a range of vegetation worth preserving in the Taehwa River water system was determined, and hyperspectral images of drones were acquired (August, October), and the results were presented through DVI(Normalized Defference Vegetation Index), EVI(Enhanced Vegetation Index), PRI(Photochemical Reflectance Index), ARI (Anthocyanin Reflectance Index) index analysis. In addition, field spectral data and VRS-GPS(Virtual Reference System-GPS) surveys were performed to ensure the quality and location accuracy of the spectral band. As a result of the analysis, NDVI and EVI showed low vegetation vitality in October, -0.165 and -0.085, respectively, and PRI and ARI increased to 0.011 and 7.588 in October, respectively. For general vegetation vitality, it was suggested that NDVI and EVI analysis were effectively performed, and PRI and ARI were thought to be effective in analyzing detailed characteristics of plants by spectral band. It is expected that it can be widely used for park design and landscape information modeling by using drone image information construction and vegetation information.

• Journal of Environmental Impact Assessment
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• v.20 no.1
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• pp.37-48
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• 2011

Recently, the social and environmental functions of nature river are important due to the increase of expectation for river restoration. So it should be considered the effect of vegetation affecting the conveyance capacity and hydraulic resistance. However, it has not yet proposed a objective standard and modeling method to estimate the effect of conveyance capacity according to vegetaion distribution in the watercourse such as water level or velocity. Therefore, this study simulates the variations of water level and velocity using 3-dimensional hydrodynamic model, EFDC, to consider a conveyance capacity in downstream of the Soyang Reservoir. The simulation results were validated using statistical index such as F-test and T-test. As results, the water level rises about 0.01 to 0.47m and velocity difference are about -0.95m/s to 0.23m/s.

• Journal of Industrial Technology
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• v.35
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• pp.55-58
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• 2015

Natural shifting of rivers has been disturbed by anthropological activities. Urbanization in Kathmandu has been encroached the natural floodplain of Bagmati and currently channeled by training walls. The study compares the change in shape of Dhobikhola, a small tributary using 1966 and 2014 satellite images. It has been found that the original shape is heavily changed over time at the beginning and end section of river under study. The river width is now fixed by training walls and roads along the banks. Using multiple data sets like satellite images and GIS analysis, these shifts can be easily detected to plan for management and restoration of physical and ecological behaviors of rivers.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.64-67
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• 2006

The main purpose of this research was to investigate the effects of urbanization on the groundwater system in the Gap river basin, a sub-basin of the Geum river basin. In this analysis, we constructed a water cycle analysis system using SWAT. Then, changes in soil moisture and recharge rate due to land-use changes were investigated using different land-use data estimated in 1975 and 2000. Simulation results were analyzed for both draught (2001) and flood (2003) years to take into account different hydrologic conditions. It was shown that recharge rate in the most urbanized area (31% change) was reduced by 17% for both periods due to urbanization. The results also indicated that soil moisture decrease due to urbanization was more sensitive in the drought year (2001) than in the flood year (2003), We expect that the results of this research can contribute to providing useful information for managing urban rivers considering river restoration and flood control.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.324-329
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• 2015

For the restoration of lateral connectivity between rivers and floodplains, it is important to find the isolated former floodplain (IFF) and to characterize its land use in Korean rivers which were channelized by levee constructions for flood protection. The aim of this study is to map the IFF and to assess its land use pattern in the Nakdong River, Korea. The isolated former floodplain was explored by being overlapped on a digital elevation model (DEM), digital topographic map and design flood level using a geographical information system (GIS) in the Nakdong River basin. The land use of the identified IFF was classified by land-use map. The total number of IFFs was 384 and their total area was $291km^2$. While IFFs were usually surrounded by mountain forest in the upper river area, they tended to be located on wide plain areas in the downstream area of Nakdong River. The land use pattern of IFFs was mostly farmland (73.9%) and urban areas (12.7%) in the river. The results of delineation and land use analysis of isolated former floodplain in the Nakdong River will be used as a base line data for planning stream restoration.

• Journal of Conservation Science
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• v.32 no.3
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• pp.395-402
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• 2016

The impact of a large water control project on surrounding environment(temperature and relative humidity, precipitation, wind speed, present weather and visibility) was monitored. The survey have targeted on Silleuksa temple which is located in the waterside. The number of foggy days emerged as an environmental factor that can cause damage to cultural heritage. Under construction of weir since 2011, monthly relative humidity of Yeoju and Icheon was dropped to 9.6%. It depends on decrease in the number of raining days and precipitation of each year. Silleuksa temple is contiguous to Namhan River and only 100 m away from the waterside. Average wind speed is 0.5 m/s. Silleuksa has a site environmental factors which is often foggy. The number of foggy days of Silleuksa temple declined to 53 days soon after weir's completion. In case of fog, relative humidity of outside was higher than that of outside and inside of Josadang Shrine. Relative humidity difference of outside and inside of Josadang Shrine was 5.4% on average. Relative humidity of the number of foggy days is 6.3% higher on average than that of fine days. The width and dimensions of Namhan River increased by 1.45 times after weir's construction. It can change the number of foggy days. A long-term monitoring is positively necessary on fog occurrence and relative humidity.

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.255-264
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• 2020

The use of fishway has been investigated up to 2~9 years, continuously each month and over the long term that installed in 6 domestic rivers. The fish's use of fishway has been investigated as direct collection by trap in exit section of the fishway. The population structure of fish using 6 fishway and the fish that live in the river showed difference. About 2 to 7 species of fish took possession of more than 80% of total use of fish in fishways. This seems to be not the results of attraction flow in fishway but specialized result of physiology characteristic followed by species of fish. In addition, the distribution of fish species using fishway was different with the fishways installed in river. This difference seems to be consequence of the place that of the river and fishway types. Generally, the fish species were less and had high ratio of home migratory fish in vertical slot type fishway, which shows relatively fast velocity of water flow. This analysis result of major fish species using fishway can be used in planning fishway and to choose major targeted species for the planning.