• Journal of Wetlands Research
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• v.24 no.4
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• pp.354-366
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• 2022

To analyze the distribution of plant communities growing in river wetlands and the relationship between biotic and abiotic environmental factors, plant communities and environmental factors were investigated in river wetlands in the Boseong River. The Boseong River Wetland, the research site, consists of Hwapyeong Wetland, Bangujeong Wetland, and Seokgok Wetland. From June to September 2022, a plant community survey was conducted from the perspective of physiognomical vegetation, and the coverage of the emerging species followed the Braun-Blanquet scale. Plant species and the coverage of each species were recorded in the quadrant for plant community survey, and the cover of the quadrant, the total number of species, and the number of exotic species were measured as biological factors. As abiotic factors, altitude, orientation, inclination, soil texture, litter layer depth, dominant species diameter at breast height, and topography were recorded. In a total of 50 square plots, the most common Salix koreensis and Phragmites japonicus communities were found, and the community with the highest Shannon species diversity index was Phragmites japonicus-Echinochloa caudata community. As a result of ordination analysis by DCCA, the most significant clusters were separated according to topographic factors such as leeve, leeve slope, upper floodplain, lower floodplain, upper waterside, middle waterside, lower waterside, river island and opem water. As rare plants that need to be preserved in river wetlands, Hydrocharis dubia and Penthorum chinense were found in lower waterside, and it was found that the management of the river in the reservoir is necessary in line with the topographical distribution of ecosystem-disrupting plants, such as Paspalum distichum var. indutum.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.183-191
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• 2009

This study was to evaluate ecological health of Dongjin River in October 2007. The ecological health assessments was based on the Index of Biological Integrity (IBI), Qualitative Habitat Evaluation Index (QHEI), and water chemistry. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. We also analyzed spatial patterns of chemical water quality over the period of 2005${\sim}$2008, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. In Dongjin River, values of IBI averaged 19 (n=3), which is judged as a "Fair" condition after the criteria of Barbour et al. (1999). There was a distinct spatial variation. IBI score at Site 1 was estimated as 28, indicating a "Good" condition whereas, IBI at Site 2 and Site 3 were as 18 and 12, indicating "Fair" and "Poor" condition, respectively. Habitat analysis showed that QHEI values in the river averaged 117 (n=3), indicating a "Fair${\sim}$Good" condition after the criteria of Barbour et al. (1999). Values of BOD and COD averaged 2.3 mg $L^{-1}$ (scope: 0.1${\sim}$8.9 mg $L^{-1}$) and 5.5 mg $L^{-1}$ (scope: 1.8${\sim}$12.6 mg $L^{-1}$), respectively during the study. Total nitrogen (TN) and total phosphorus (TP) averaged 2.7mg $L^{-1}$ and 0.127mg $L^{-1}$, respectively, and the nutrients showed large longitudinal gradients between the upper and lower reach. Overall, dataset of IBI, QHEI, and water chemistry showed that river health was a gradual decline at upstream to downstream. So, Dongjin River should be protected from habitat disturbance and chemical pollutions.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.249-257
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• 2010

The purpose of this paper is to weigh the possibility of endangered Jang-hang wetland at the estuary of Han River to be included on the Ramsar List of Wetlands of International Importance and come up with ways to manage the wetland depending on its biotope patterns. The target area is located between Gimpo bridge and Isanpo I.C. with about $2.7km^2$ area. Through the analysis of RIS(Information Sheet for Ramsar Wetlands), it was known that the wetland is located on the sedimentary topography and formed as a result of sediment at the estuary of the river owing to the concentration of rainfall during summer. The vegetation environment in the area is divided into brackish water and fresh water areas depending on salinity. Rhizosphere soil(RS) of the area was analyzed to be Silt loam while bottom RS to be Sand loam. The plant ecology was composed of 52 families 135 species and 11 varieties and 146 types. Among indigenous species found are Salix koreensis, Phragmites communis and Miscanthus sacchariflorus. The analyzed results of the actual vegetation showed that willow community accounts for 37% of the area and rice field is 13.5%. As for animal ecology, total of 62 species and 25,977 individual wild birds were observed. After comparing and analyzing the RIS we compiled with the Ramsar Site designation standards, it turns out that the Jang-hang wetland meets criteria 1(biographic region), criteria 2,3 and 4(species and ecological communities) and criteria 5 and 6(water birds). Thus, Jang-hang wetland is eligible for the Ramsar site. As a result of establishing and evaluating the biotope types for setting management areas, Jang-hang wetland has a total of 13 different types, and the grade I represents 75.4% of the area while the grade III 0.8% of the land status. We categorized four management zones for the wetland depending on the biotope patterns - preservation, restoration, use and buffer zones and suggested management methods for each zone.

• Journal of Soil and Groundwater Environment
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• v.11 no.2
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• pp.45-55
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• 2006

A 2-D unconfined flow model is developed to analyze annual variations of groundwater level and bank filtration rate (BFR) for an experimental riverbank filtration site in Koryeong, Korea. Two types of boundary conditions are examined for the river boundary in the conceptual model: the static head condition that uses the average water level of the river and the dynamic cyclic condition that incorporates annual fluctuation of water level. Simulations show that the estimated BFR ranges $74.3{\sim}87.0%$ annually with the mean of 82.4% for the static head boundary condition and $52.7{\sim}98.1%$ with the mean of 78.5% for the dynamic cyclic condition. The results illustrate that the dynamic cyclic condition should be used for accurate evaluation of BFR. Simulations also show that increase of the distance between the river and the pumping wells slightly decreases BFR up to 4%, and thereby indicate that it is not a critical factor to be accounted for in designing BFR of the bank filtration system. A sensitivity analysis is performed to examine the effects of model parameters such as hydraulic conductivity and specific yield of the aquifer, recharge rate, and pumping rate. The results demonstrate that the average groundwater level and BFR are most sensitive to both the pumping rate and the recharge rate, while the water level of the pumping wells is sensitive to the hydraulic conductivity and the pumping rate.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.96-105
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• 2010

This study identified the dynamic process of sandbar and vegetation distribution of the sandbar on the Tan-cheon River. The study area is located in the lower reaches of the Tan-cheon River that has been managed as an Ecosystem Reserve Area since 2002. For the study, the geomorphological process was analyzed through mapping analysis using a satellite image followed by analysis of the vegetation distribution through an on-site survey. The major findings were as follows : First, In the fluvial geomorphic process, various kinds of sandbars were developed in 1990s, the morphologic characteristics changing continuously. Second, In the distribution of vegetation on the sandbar, the sandbar shore was covered with bare sand substrate or intermittent annual vegetation because of the periodic fluctuation of the water-level due to intensive disturbances. Third, In the relationship between the sandbar formation and vegetation, four types of sandbars were classified: channel-shore stable bar, channel-shore unstable bar, mid-channel stable bar and mid-channel unstable bar, according to the fluvial disturbance & vegetation process. The study verifies that the vegetation distribution is reciprocally related to the geomorphological process. Accordingly, it is meaningful in the selection of plant species and the planting area of the sand bar. However, it is limited to the planting guidelines on river restoration projects. More diverse on-site experimental studies should be conducted.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.150-160
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• 2010

The objective of this study was to analyze long-term temporal trends of water chemistry and spatial heterogeneity for 7 sampling sites of the Hyeongsan River watershed using water quality dataset during 1999 to 2008 (obtained from the Ministry of Environment, Korea). The water quality, based on eight physical and chemical parameters, varied largely depending on the years, seasons and sampling sites. Seasonal and annual means of conductivity, used as a key indicator for a ionic dilution declined during the monsoon season and TN, based on overall mean of all sites, showed marked declines during the monsoon, compared to those of the premonsoon. In the mean time, BOD and COD had no significant relations with a precipitation, in spite of some differences in the sampling sites. In contrast, major input of SS occurred during the period of summer monsoon season. Spatial trend analyses of all parameters, except for DO and temperatures, showed that gyeongju city acted as a point source, and thus, water quality at the location of Site 4 declined abruptly, compared to locations of Site 1~2. Based on overall dataset, efficient water quality management in the point source tributary streams is required for better water quality of the main Hyeongsan River.

• Journal of Korea Water Resources Association
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• v.54 no.8
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• pp.567-576
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• 2021

Climate change threatens the security of domestic water resources in South Korea. To overcome the potential water shortage, various approaches are being studied by alterning the operation of dams or by integrated operation of multiple dams and reservoirs. However, most of the related researches were developed and applied for multi-purpose dams, and few studies were conducted for the hydropower dams. The main purpose of the hydropower dam is to generate electric energy; however, the potential water shortage due to prolonged droughts brings the idea to supply water from the hydropower dam in the basin. To that end, it is required to estimate the water supply ability of the hydropower dams. In this study, we proposed a methodology to classify the hydropower dam into a "storage-type" and "run-of-river type" dam. The proposed approach was demonstrated using the hydropower dams located in North-han River basin. The results of this study are expected to contribute for further analysis of the hydropower dams, such as evaluation of water supply capacity and drought mitigation purpose operation of the hydropower dams.

• 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.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.534-537
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• 2005

Polarization of the radar wave refers to the ellipticity angle and orientation angle of the polarization ellipse. An evaluation of the polarization response can help understand the scattering mechanisms involved for a particular area of interest or provide information for image classification and algorithm section. C- and L-band polarization responses measured at urban area show the results that the polarization behavior for dihedral comer reflector or short, thin cylinder reflector appears at located in city streets or buildings site which are lined up and the polarization behavior for a large conducting sphere appears at parts of test site particularly river, flat, and vegetated areas. Also, the co- and cross-polarized response graphs and polarimetric parameters are discussed.

• Journal of the Korean Institute of Rural Architecture
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• v.9 no.3
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• pp.121-128
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• 2007

This paper aims to clarify the transformation and housing spatial form of the Port Settlement of Rivershore in Sangbu-village, Samrangjin. The form of site are many fixed forms, has the narrow width of a site and the length is long. Although built as a shop house those days, there is much what changed to the residence now. If the space composition of a residence is seen, it is one building and what goes in and out through the door is common. When a focus is applied and analyzed to the transformation of a residence, position change of formation of the door and an entrance is noticeable.