• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.2
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• pp.25-33
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• 2002

This study was carried out to select the utilizable vegetations for the stabilization of slopes and river banks, landscape creation and water quality cleansing in dams, lakes and streams. In this study, 10 herbaceous plants were investigated for their survival and growth characteristics under complete and partly flooding conditions in the nursery. The ranking order of flooding tolerance based on survival ability showed that Iris pseudoacorus, Phragmites communis and Phragmites japonica were first, Typha angustata, Miscanthus sacchariflorus and Pennisetum alopecuroides were second, and Cymbopogon tortilis, Miscanthus sinensis, Kummerowia striata and Lolium multiflorum were last. That of flooding tolerance base on growth ability showed that Iris pseudoacorus, Phragmites communis, Phragmites japonica, Typha angustata and Miscanthus sacchariflorus were first, Pennisetum alopecuroides, Miscanthus sinensis and Kummerowia striata were second, and Cymbopogon tortilis and Lolium multiflorum were last. Espcially, Miscanthus sacchariflorus, Iris pseudoacorus, Phragmites japonica and Phragmites communis showed good survival and growth abilities when they were complete flooded for 60 days. Also high flooding tolerant species grow as better as flooding period longer under the partly flooding condition. It was found that Pennisetum alopecuroides and Kummerowia striata have excess moisture tolerance because they showed good survival and growth under the partly flooding condition. This study confirmed that the possibilities of utilizing Iris pseudoacorus, Typha angustata, Phragmites japonica, Phragmites japonica, Phragmites communis, Miscanthus sacchariflorus, Pennisetum alopecuroides and Kummerowia striata as the efficient plants for vegetation measures on the flooded slopes of dam and various impoundment sites.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.15-26
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• 2013

In recent years, river maintenance projects using natural methods have been continuously implemented in urban areas and methods emphasizing ecology are being developed and constructed in revetment areas. However, there is insufficient technical review on the hydraulic stability of those revetment methods during the event of flood. Therefore, a hydraulic analysis is necessary for the stream where revetments are applied. This study was conducted to develop an objective test method for the hydraulic stability of green revetment media. For this purpose, hydraulic model tests were performed for the green base materials for revetments. Tests were conducted using experimental devices for the hydraulic model which were installed to simulate the rapid current during the flood. Loss of soil by the hydraulic condition was compared and analyzed with that of dry green revetment media, and the evaluations were made on the corrosion resistance, tractive force, and contractile force. Test results showed that green revetment media had higher corrosion resistance in non-vegetation condition compared to dry green revetment media, and the loss of base materials by the rooting of vegetation showed significant reduction by the vegetation. In addition, results of the allowable tractive force of the base material indicated it is relatively stable in vegetation condition but scouring can occur in non-vegetation condition. Therefore, the development of vegetation in revetment areas is anticipated to be effective for the stability of revetment areas by reducing external forces interacting with the corrosion resistance and stream bank. The green revetment media in expected to contribute to the stability of revetment areas.

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.267-276
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• 2013

An Improvement of channel structure for sound fish habitat suitability enhancement is investigated. The restoration target species of Zacco Koreanus which is represented a sound aquatic ecosystem is selected by investigating results of the fish fauna and the river environments. The changes of lower channel width for enhancing suitability indices for water velocity and depth result in habitat suitability enhancement in general by PHABSIM simulation. The habitat suitability enhancement is not guaranteed consistently by the changes of lower channel is confirmed. The optimal lower channel widths at each reach are presented by genetic algorithm of optimization which is considering the enhancement of suitability indices for water velocity and depth with given instream flows. The suggested plan of the lower channel modification will contribute to the various projects for the environmental improvement of aquatic system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.4
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• pp.1-13
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• 2017

The purpose of this study is to analyze a term of decade of water quality data of the Mulgum intake station on the Nakdong river(dam) to find the cause of algal blooms and to set an alternative to prevent artificial lake water pollution. Our study shows that water quality changes have regular periodic regularity and there was a certain correlation between specific analytical items. According to the analysis results of each factor, the decline in precipitation was not the main reason for algal blooms. TP concentration had a slight effect on Chl-a concentration but was not a limiting nutrient of a bloom. TN concentration had a strong correlation with Chl-a and strongly negative correlation with temperature, but was not a bloom's limiting nutrient, and was only a dependent variable. As the temperature was negatively correlated with the Chl-a concentration, it is found that the aspect of the ecological influence of the temperature was the most important factor of the phytoplankton concentration change. The N/P ratio lies under a power function with a high degree of reliability by the TP concentration, and the phenomenon appeared to be the same as the results of two other comparative areas. This result confirms that TN is dependent on TP and the biota in the lake that TN is a dependent variable whose concentration is determined by TP it. In conclusion, the increase in lake bloom is the result of a food chain change, and it is necessary to control the ecosystem by the food chain in the lake in order to reduce the lake's bloom. In particular, it is important to keep the benthic ecosystem as wide as possible in the aerobic state.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.5
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• pp.59-66
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• 2017

Preeminent water treatment plans are essential to preserve the water quality of aquatic biotopes. Previous studies have not been sufficient to provide cost-effective maintenance method since they focused only on the purification of deteriorated water that requires a continuous supply of clean water. This study proposes an economical method of water quality maintenance using water treatment media block constructed vertically using porous ceramics, zeolite, and river pebble. The water treatment media block does not require a separate purification area because it functions as a purifier within the ecological pond which can maximize the biotope area. To evaluate the performance of the water treatment media block, we longitudinally tracked the change of water quality indicators (pH, TDS, COND, DO, T-P, T-N, COD) suggested by Water Environment Standards, Ministry of Environment, Republic of Korea. We compared the water quality of one control (A: general ecological pond composition method of the laminated structure) and two experimental groups (B: a combination of aquatic plants and a water treatment media block, C: a water treatment media block only). As a result, we confirmed that the water treatment media block is an efficient and economical method to maintaining the water quality of the ecological pond for a long time. The water treatment media block will be a great help in providing a better aquatic biotope space for aquatic insects and fishes living in clear water.

• Journal of architectural history
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• v.16 no.2
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• pp.59-78
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• 2007

Studies and reports on buddhist temples in Goryeo dynasty are rarely In the present situation. At this point of time new excavational reports and historic records offer many materials to understand a architecture in Goryeo period. Especially, temple site have various transitions, it is of great value to study. This article attempted a restorative study of a location, function, spacial arrangement, structure, building age is based on a measure and transition of temple layout that is based on the excavational result and related historic documents about Godal temple site in Yeoju. Gadal temple site was a representative Zen buddhist temple in Goryeo Dynasty. It was difficult of access by watercourse because it was located in an inland in the upper Han River. Archaeological research and historical records has reveals that the temple was constructed with a minium of four levels[six terms]. We could recognized the central site of temple and buildings were constantly established, enovated or collapsed. It has went through many transition according as it encountered new sects and doctrines. Also it should perform various functions and overcome given conditions. Ultimately it let see greater diversity in the spacial composition, and layout. That is to say it were planed several separate areas, each was consisted of main buildings, once again was integrated into one temple.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.52-60
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• 2004

In order to analysis of the water pollution of the Anyang stream(one of the biggest branch streams of the Han River) and its main tributaries, the geological and topographical and rainfall features in its basin were investigated. To do this, the water samples were collected 23 points of the upper, mid and down of Anyang stream and its tributaries and were analyzed based on the chemical methods, Korean Biotic Index(KBI) and Saprobien systems. The Anyang stream basin has a characteristic of topographical torrential heavy rainfall like a typical rainfall feature in Korea. The concentration and the outflow rate of rainfall is very different in seasonal, and water pollution in dry season is especially severe. After 1997, although the water quality status of stream has been improved gradually, the concentration of T-N and SS at the upstream is increased due to the deficiency of facility used for collecting wastewater released from industrial factories, livestock farms and residential areas. The mainstream of the Anyang stream is classified into the 5th grade water as polysaprobic water area according to Saprobien system and the biotic index is over 2.5 in overall. Most of tributaries have 1~3 grade water limit with ${\alpha}$- and ${\beta}$-mesosaprobic except the upper and mid streams of Samsung tributary, in which pollution status is the lowest part. Though Sambong tributary is ${\alpha}$-mesosaproboic, biotic index is low because of the appearance of abundant benthos animals in farming and fishing villages.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.5
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• pp.10-18
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• 2005

The research was carried out to define the morphological and growth characteristics of Poa pratensis L.(Kentucky bluegrass) 'Sewon' in native to Korea. Poa pratensis 'Sewon' was collected at the terrace land on the river in Guiman-ri, Cheongcheon-myeon, Goesan-gun, Chungcheongbuk-do on May 5, 1995. The collected Poa pratensis 'Sewon' was grown under non-mowing naturally growing condition. The morphological characteristics of Poa pratensis 'Sewon' are as follows. : The height of plant was 21.6cm but was increased to 33cm at the flowering time. The height of first node from the base was 5.0cm and the length and width of leaf were 9.6cm and 4.1cm, respectively. The length of inflorecences was 37.8cm and the length of a spike was 7.3cm. Based on these morphological characteristics, Poa pratensis 'Sewon' was defined to dwarf~medium and coarse texture type Kennturky bluegrass. 1 to 9 scale of visual quality, visual color and visual density were measured. Poa pratensis 'Sewon' showed best turf qualities among native Kentucky bluegrasses. In spring and fall growing season, Poa pratensis 'Sewon' were measured to be excellent performances for turf qulities similar to foreign excellent quality cultivars such as Midnight, Nuglade and Brilliant Kentucky bluegrasses. But turf quality of Poa pratensis 'Sewon' decreased by plant disease according to temperature increase in summe compared to foreign excellent quality cultivars. So, Poa pratensis 'Sewon' should be improved of disease tolerent quality by incessant breeding work in order to compete foreign excellent quality cultivars.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.4
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• pp.97-110
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• 2020

This study conducted observations at 72 traffic lights and road signs in Sejong-si, Korea from March to June 2019 in order to analyze nest-site, nest-site characteristics and feeding behavior in Tree sparrow (Passeer montanus) in urban. Feeding behavior during breeding season in 2019 was investigated at 10 Town representing traffic facilities installed on the road located in the center of the city and 10 Riverside Geumgang river's riverside road. We fitted both general linear model and regression model to our field data and estimated the spatial variation of initial date of the first feeding (i.e., being date of breeding) and the total number of caterpillar fed by parents per hour. Our results showed that the frequency of nest building on artificial structures, such as traffic lights, was about 26% higher and about 8 days earlier in the riverside. In particular, the first feeding was significantly faster when the nearest distance between nest to green field as foraging site was shorter whereas there was no significant effect of the number of nest within 50 meters on the first feeding. Number of caterpillars fed by parents was higher in the Riverside than in the Urban, and especially the number in the second brood was sharply decreased in the Urban. As we estimated average amount of caterpillars per hour to 446 traffic safety facilities in Sejong-si, it was estimated that Tree sparrows fed 18,742.8 caterpillars per hour during the breeding season. In this study, we showed that characteristics of nests built in artificial structures and feeding behavior in order to analyze effects of environmental condition in urban on life-history traits during the breeding season. Finally, we discussed the conservation of birds in urban and pest control effects.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.2
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• pp.163-174
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• 2021

Heatwaves are one of the most common phenomena originating from changes in the urban thermal environment. They are caused mainly by the evapotranspiration decrease of surface impermeable areas from increases in temperature and reflected heat, leading to a dry urban environment that can deteriorate aspects of everyday life. This study aimed to calculate daily maximum ground surface temperature affecting heatwaves, to quantify the effects of urban thermal environment control through water cycle restoration while validating its feasibility. The maximum surface temperature regression equation according to the impermeable area ratios of urban land cover types was derived. The estimated values from daily maximum ground surface temperature regression equation were compared with actual measured values to validate the calculation method's feasibility. The land cover classification and derivation of specific parameters were conducted by classifying land cover into buildings, roads, rivers, and lands. Detailed parameters were classified by the river area ratio, land impermeable area ratio, and green area ratio of each land-cover type, with the exception of the rivers, to derive the maximum surface temperature regression equation of each land cover type. The regression equation feasibility assessment showed that the estimated maximum surface temperature values were within the level of significance. The maximum surface temperature decreased by 0.0450℃ when the green area ratio increased by 1% and increased by 0.0321℃ when the impermeable area ratio increased by 1%. It was determined that the surface reduction effect through increases in the green area ratio was 29% higher than the increasing effect of surface temperature due to the impermeable land ratio.