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

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.95-106
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• 2009

The Shihwa constructed wetland was established for the treatment of severely poluted water from Banwoul, Donghwa and Samhwa streams. This study was focused on investigating the structure of epiphytic diatom communities on reed (Phragmites communis) planting area at Banwoul high wetland (3 stations) and low wetland (3 stations) from March to October 2005. The concentration of T-N of inlet stations from the streams were decreased by flowed through the wetland, but the concentration of T-P were increased at outflow part. Epiphytic diatoms on the reed were a total 109 taxa which were composed of 103 species, 5 varieties, 1 unidentified species. The standing crops were rapidly decreasing tendency from spring to autumn but chlorophyll-a concentration were showed a very irregulated changes. Dominant species were 6 taxa which were Achnanthes minutissima in the early investigation, and were changed to the genus Navicula and the genus Nitzschia in the summer. DAIpo were ranged the values of $20.2{\sim}51$, which were mesosaprobic states at the high wetland and ranged the values of $12.4{\sim}52$, which were polysaprobic to mesosaprobic states at the low wetland. TDI were ranged the values of $28.8{\sim}94.5$, which were oligotrophic to eutrophic state at the high wetland and ranged the values of $33.3{\sim}89.7$ which were mesotrophic to eutrophic states at the low wetland. The healthy assessment (DAIpo and TDI) of water ecosystem were showed clean-bad from spring to autumn. These epiphytic diatom communities were determinated by the biological factor such as the growth of reed and the physical factors such as water temperature, light penetration and SS and so on.

• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.791-799
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• 2019

This study explained the historical changes in the habitat structures based on the aerial photographs (1948, 1967, 1973, 1989 and 2010) of the mid-stream reach of the Mangyeong River. The habitat structure was divided into landforms and aquatic habitats. The landform was classified into bare land, vegetated land, water surface, farmland and artificial land. The aquatic habitat was classified into natural riffle, artificial riffle, run, head wando, tail wando, mid wando, pond and chute channel. The ratio of bareland decreased, and water surface and vegetated land increased after the excavation in 1970s and since the construction of weir in 1980s. As historical changes of aquatic habitat, ratio of run decreased sharply while mid wando increased sharply. aquatic habitats such as head wando, tail wando, and pond located on bars decreased dramatically.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.523-532
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• 2021

The treatment of acid rock drainage was reviewed and evaluated for the case of pyrite rocks distributed in a highway embankment. During the highway's construction, neutralization using alkaline water repellent was applied to the embankment section to prevent acid rock drainage. However, it still occurred long after the construction was completed owing to rain infiltration, and the acid rock drainage polluted the surrounding soils and streams. To solve this problem, treatment facilities such as SAPS (Successive Alkalinity Producing Systems) or ecological wetlands and sand filtration were installed. After the installation of the treatment facilities, the effluent and soils contaminated by acid rock drainage nearby the outlet of the facilities were analyzed and evaluated for a period of years. Measurements of the pH of the effluent and analysis of the heavy metal contamination of the soils confirmed that the neutralization treatment for acid rock drainage is being performed properly and that contamination of heavy metals in the acid rock drainage is also being stably controlled by the treatment facilities.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.406-414
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• 2022

Bolboschoenus planiculmis has been acknowledged as a key species in whooper swans (Cygnus cygnus) habitat by providing food for this migratory waterfowl. B. planiculmis wetlands are being degraded by water shortages and salinization caused by anthropogenic activities and climate changes. In 2004, the distribution of B. planiculmis in the tidal flats of the Nakdong Estuary was 2,475,568 m², and in 2021, the distribution area was 798,731 m², which decreased by 32.3%. In order to restore the degraded B. planiculmis wetlands, shoot transplantation and seed sowing were tentatively used in three places with different salinity and water levels. The average density per unit area in September at the optimal growth period after planting were A (fresh water level 50 cm) 58±15.65 m^-2, B (brackish water level 0~5 cm) 188±63.83 m^-2, C (brackish water level 0 cm or less) 188±45.13 m^-2. The tubers were observed as A 0 g dw m^-2, B 25.32±2.94 g dw m^-2, and C 13.39±0.91 g dw m^-2. Tubers were distributed in the soil, with only 3.0% at the 10~20 cm depth but 97.0% at the 0~10 cm depth. In contrast, the germination rate of B. planiculmis seeds was observed to be 0%. Results of this study provide technical support for the restoration of B. planiculmis wetland and the improvement in the quality of whooper swans habitat.

• Journal of The Geomorphological Association of Korea
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• v.17 no.3
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• pp.17-30
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• 2010

This paper aims to excavate and make storytelling of cultural landforms around Shincheon, Geumho river in Daegu and then to build the strategy for making its application. The main results are as follows. 1) There are main cultural landforms such as Yongdubawi(龍頭岩, river cliff), river cliff, rock shelter(岩蔭), sheeting joint landform, river cave, tor, etc. around Shincheon. 2) there are main cultural landforms such as riverine wetland, ferry, point bar, river cliff, Hwadam(畵潭, pool), Donghwacheon(stream), Mutae(無怠), Chimsan(hill), Yeonamsan(hill), Sanghwadae(river cliff), etc. around Geumho river. 3) It is necessary to excavate and restore cultural landforms around Shincheon and Geumho river for protection, Also the valuable cultural landforms should be designated as cultural assets in order to prevent damage. 4) Considering from application of cultural landforms around Shincheon, natural observation site need to be designed for experiencing culture, history and ecological environment. However, in viewpoint of application of cultural landforms around Geumho river, it is much better to plan a few of Geumho river cultural landform trails for self-guided tour.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.14-35
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• 2023

Freshwater and brackish blue-green algae were collected at 43 freshwater and brackish sites (including lakes, ponds, swamps, streams, and rivers and estuaries) throughout South Korea from March 2017 to October 2018, and were identified using light microscopy. A total 223 taxa in freshwater and 230 taxa in brackish waters in 2017 and 274 taxa in fresh and brackish waters in 2018 were identified and among them, 20 taxa were unreported taxa of blue-green algae in Korea; The new recorded taxa were Aphanocapsa marina, Calothrix fusca f. durabilis, Calothrix littoralis, Calothrix parva, Chamaesiphon minimus, Chroococcidiopsis cubana, Chroococcidiopsis fissurarum, Coelosphaerium aerugineum, Dolichospermum mendotae, Eucapsis alpine, Gomphosphaeria cordiformis, Gomphosphaeria natans, Merismopedia danubiana, Lynbya aestuarii var. gaditana, Tolypothrix tenuis, Pseudocapsa maritima, Pseudocapsa sphaerica, Pseudophormidium tenue, Trichodesmus sp. and Woronichinia elorantae.

• Journal of Wetlands Research
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• v.22 no.3
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• pp.194-199
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• 2020

Unlike in the past, the world is facing water shortages due to climate change and difficulties in simultaneously managing the risks of flooding. The Four Major Rivers project was carried out with the aim of realizing a powerful nation of water by managing water resources and fostering the water industry, and the construction period was relatively short compared to the unprecedented scale. Therefore, the prediction and analysis of how the river environment changes after the Four Major Rivers Project is insufficient. Currently, part of the construction section of the Four Major Rivers Project is caused by repeated erosion and sedimentation due to the effects of sandification caused by large dredging and flood-time reservoirs, and the head erosion of the tributaries occurs. In order to solve these problems, the riverbed maintenance work was installed, but it resulted in erosion of both sides of the river and the development of new approaches and techniques to keep the river bed stable, such as erosion and excessive sedimentation, is required. The water agent plays a role of securing a certain depth of water for the main stream by concentrating the flow so much in the center and preventing levee erosion by controlling the flow direction and flow velocity. In addition, Groyne products provide various ecological environments by forming a natural form of riverbeds by inducing local erosion and deposition in addition to the protection functions of the river bank and embankment. Therefore, after reviewing the method of determining the shape of the Groyne structure currently in use by utilizing the mobile limit flow rate and marginal reflux force, a new Critical Movement Velocity(${\bar{U}}_d$) and a new resistance coefficient formula considering the mathematical factors applicable to the actual domestic stream were developed and the measures applicable to Groyne installation were proposed.

• Korean Journal of Environmental Agriculture
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• v.33 no.3
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• pp.169-177
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• 2014

BACKGROUND: The ferronickel and rapid cooling slags used in present study are industrial wastes derived from a steel factory in Korea. These slags are used as almost road construction materials after magnetic separation. However, the use of slag to remove phosphorus from wastewater is still a relatively less explored. The objective of this work was to evaluate the feasibility of ferronickel slag (FNS) and rapid cooling slag (RCS) as sorbents for phosphorus removal in wastewater. METHODS AND RESULTS: Adsorption experiments were conducted to determine the adsorption characteristics of the FNS and RCS for the phosphorus. Adsorption behaviour of the phosphorus by the FNS and RCS was evaluated using both the Freundlich and Langmuir adsorption isotherm equations. FNS and RCS were divided into two sizes as effective sizes. Effective sizes of FNS and RCS were 0.5 and 2.5 mm, respectively. The adsorption capacities (K) of the phosphorus by the FNS and RCS were in the order of RCS 0.5 (0.5105) > RCS 2.5 (0.3572) ${\gg}$ FNS 2.5 (0.0545) ${\fallingdotseq}$ FNS 0.5 (0.0400) based on Freundlich adsorption isotherm. The maximum adsorption capacities (a; mg/kg) of the phosphorus determined by the Langmuir isotherms were in the order of RCS 0.5 (3,582 mg/kg) > RCS 2.5 (2,983 mg/kg) > FNS 0.5 (320 mg/kg) ${\fallingdotseq}$ FNS 2.5 (187 mg/kg). RCS 0.5 represented the best sorbent for the adsorption of phosphorus. In the experiment, the Langmuir model showed better fit with our data than the Freundlich model. CONCLUSION: This study indicate that the use of RCS in constructed wetlands or filter beds is a promising solution for phosphorus removal via adsorption and precipitation mechanisms.

• Journal of Wetlands Research
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• v.4 no.1
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• pp.63-85
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• 2002

This study was carried out to provide basic data for water environmental control and conservation, and to elucidate monthly water environmental factor, phytoplankton flora and dominant species that each stations was maked a selection of a sites by represent 3 branch-river in the Taejon area from Nov. 1997 to Dec. 1998. Range of water temperature was $2.4^{\circ}C{\sim}30.9^{\circ}C$(means of $16.02^{\circ}C{\sim}18.92^{\circ}C$), pH was 7.1~10.4(means of 7.40~8.68). BOD was generally under $5mg/{\ell}$ except Gap-chon kyo in Nov. and COD was measured highly by interfer of men at the each sites. Especially, occasion of Gap-chon kyo, data was estimated about 3~13 times higher than another sites. DO was showed 1.03~10.43ppm, SS was showed $1.0{\sim}120.0mg/{\ell}$ TN was that, upper stream was 0.63ppm, middle was 0.35ppm and then lower was 0.44ppm, upper stream was higher than lower. TP was at upper stream 0.03ppm, middle 0.05ppm, lower 0.06ppm, lower stream was higher than another. The phytoplankton flora was identified as total 230 taxa composed of 7 classes, 18 oders 35 families, 75 genara, 184 species, 42 virieties, 4 forms. There are composed of that, Chlorophyceae 94 taxa(40.9%), Bacillariophyceae 66 taxa(28.8%), Euglenophyceae 39 taxa(17.0%), Cyanophyceae 24 taxa(10.4%), Chrysophyceae 4 taxa(1.7%), Rhodophyceae 2 taxa(0.8%) Xanthophyceae 1 taxa(0.4%), composition of Spesies of each sites was Gapchon-kyo 119, Wonchon-kyo 94, Gasuwon-kyo and Mannyon-kyo 87, Ochung-kyo 78, Hyunam-kyo and Suchim-kyo 77, Moonchang-kyo 70 taxa and Sansung-kyo 58 taxa. Number of species was showed tendency of increase lower stream. Taejon-chon and youdung-chon and at the sites of confluence were presented Synedra ulna and Diatom vugare like bacillariophyceae, Gap-chon was dominated variously Oscillatoria princeps and chlorophyceae, confluence of 3 branch-river was presented Euglenophyceae.