• Journal of Environmental Science International
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• v.25 no.1
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• pp.41-56
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• 2016

In recent localized heavy rainfalls have been arising from abnormal climate change. People are concerning about damages with increasing the frequency of flooding. Therefore, we need to understand river hydraulic characteristics and management to reduce damage from flooding. To study hydraulic characterization of Sincheon experimental catchment HEC-RAS (Hydrologic Engineering Center River Analysis System) model which provided by U.S Army Corps of Engineers (USACE) was applied. This study analyzed and compared water level the frequency flood for 100 years and 200 years by clark unit Hydrography. The change of the water level of Daejeon bridge, Sincheon bridge and Singi bridge showed increased for all conditions. The flow rate for the Daejeon bridge and the Sincheon bridge showed an increase, but the Sinki bridge showed a decreasing flow rate overally, except for 1hour-100 years. The verification result showed that the model was able to simulate the water level with 0.4709 coefficient of determination and error ration ranging from 1 to 3%.

• Journal of Plant Biology
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• v.8 no.4
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• pp.7-25
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• 1965

In order to clearify the microflora of the lower course of the Han River and the effect of the marine water on the Han River, the study was carried out at Paldang, Kwangjang, Noryangjin, and Haengju for 4 months (from May till September in 1965). The results obtained are as follows: 1) Water temperature, transparency, light intensity, pH, silicate, and salinity were determined as environmental conditions. 2) Samples collected from 4 stations were identified and classified by Engler's classification system. It resulted in 4 Phyla, 3 Classes, 13 Orders, 25 Families, 61 Genera, 155 Species, and 16 Varieties. The total numbers of phytoplanktons identified are 171. Of the number, 106 species and 12 varieties were recorded in this paper for the first time. 3) A comparative observation on the distribution of marine phytoplanktons and salinity in the Han River showed a fact that the Han River was biologically affected in the middle portion between Noryangjin and Haengju by marine water. Furthermore, the salinity determined at Haengjuduring a day(at high tide, September 26, 1995) supported the above fact. 4) Four species among the identified species are saprobic planktons and it is regarded as the forms derived from Chunggyechon.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.282-290
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• 2017

A long-term resuspension of small particles, called persistent turbidity, is one of the most important water quality concerns in the dam reservoirs system located in North Han River. Persistent turbidity may incur aesthetic nuisance and harmful effect on the ecosystem health, in addition to elevated water treatment costs for the drinking water supply to the Seoul metropolitan area. These sufferings have been more intensified as the strength and frequency of rainfall events increase by climate change in the basin. This study was to analyze the effect of an extreme turbidity flow event that occurred in 2006 on the serial reservoirs system (Soyang-Uiam-Cheongpyung-Paldang) in North Han River. The CE-QUAL-W2 model was set up and calibrated for the river and reservoirs system using the field data obtained in 2006 and 2007. The results showed that Soyang Reservoir released turbid water, which was classified as the TSS concentration is greater than 25 mg/L, for 334 days with peak TSS of 264.1 mg/L after the extreme flood event (592.7 mm) occurred between July 10 and 18 of 2006. The turbid water departed from Soyang Reservoir reached at the most downstream Paldang Reservoir after about 20 days and sustained for 41 days, which was validated with water treatment plant data. Since the released water from Soyang Reservoir had low water temperature and high TSS, an underflow formed in the downstream reservoirs and vertically mixed at Paldang Reservoir due to dilution by the sufficient inflow from South Han River.

• Tunnel and Underground Space
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• v.6 no.3
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• pp.223-233
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• 1996

Geotechnical Information System (GTIS) for efficient management of three dimensional borehole data has been developed. Geotechnical maps in the vicinity of Bulkwangdong, Seoul station, Itaewon, Han river near Yuido, and Jungrangchon were constructed by Kriging method. In Bulkwangdong and Jungrangchon area where boundary between granite and gneiss is present, gneiss has been more weathered than granite, but in Seoul station and Itaewon area where the boundary is also present, granite has been more weathered than gneiss. It has been inferred that when Seoul granite intruded, the strength of gneiss in Bulkwangdong and Jungrangchon area was lowered by the attitude of foliation plane than in Seoul station and Itaewon area, so the gneiss has been easily fractured and weathered in Bulkwangdong and Jungrangchon area. Geotechnical map in the vicinity of Yuido showed that there is an NW-SE trend weakness zone that might be affected by major faults under Han river and it is expected that the fault zone may be present in construction area of Kyoungbu Highspeed Railway that lies below the Han river like the Subway Line No.5.

• Journal of the Korean Regional Science Association
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• v.37 no.1
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• pp.45-61
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• 2021

This research purposes to design a methodological framework to suggest the optimal method to resolve the conflicts of stakeholders surrounding the water use charge of the Han River region, and to use the analysis results to provide the direction of policy. For this, it was preceded that the process of understanding the mechanisms of the multifaceted conflict between decision makers taking different positions over water use charge of the Han River region, and an optimal method to resolve the conflict of water use charge of the Han River region was derived by using a graph model for conflict resolution(GMCR). According to the analysis results, the optimal state to find a solution to the water use charge of the Han River is that the Seoul-Incheon-Gyeonggi region pays the charge according to the original rate while Seoul-Incheon requesting discount the water use rate. In addition, the Han River management committee should establish policies desired by Seoul-Incheon-Gyeonggi region including rationalization of the decision-making structure to determine the rate of water use charge, making the basis to support the Han River management fund system for the Seoul-Incheon region, and transparent management of the Han River management fund system considering the characteristics of beneficiary regions and residents. This study is expected to provide objective decision-making information in establishing environmental policy directions related to conflict resolution in the water use charge of the Han River region and to offer a methodological basis for similar follow-up studies related to conflicts derived from sharing nature environment.

• Journal of Ecology and Environment
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• v.37 no.1
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• pp.1-11
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• 2014

To understand the effects of fluctuations in dam discharge due to river environments and phytoplankton communities, we monitored such environments and phytoplankton communities biweekly, from February 2001 to February 2002 and from February 2004 to February 2005, in the lower Han River (LHR), South Korea. The phytoplankton abundance during the dry season was approximately two times higher than that during the rainy season. In particular, fluctuations in diatom assemblages, which constituted over 70% of the total phytoplankton abundance, were affected severely by the changes in the discharge. When a large quantity of water in a dam was discharged into the LHR, the conductivity and the concentrations of total nitrogen (TN), total phosphorus (TP), and dissolved inorganic phosphorus (DIP) decreased rapidly, whereas the concentrations of suspended solids (SS), dissolved inorganic nitrogen (DIN), and dissolved silica (DSi) increased immediately. Time-delayed relationship also revealed that the dam discharge had an immediately significant negative relationship with phytoplankton abundance. On the whole, fluctuations in phytoplankton communities in the LHR were influenced much more by hydrodynamics such as dam discharge than by the availability of nutrients. Thus, the variability in these concentrations usually parallels the strength of river flow that is associated with summer rainfall, with higher values during periods of high river discharge.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.704-716
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• 2018

The aim of this study is to examine the characteristics analysis of the discharge and water quality based on TPLMS (Total Pollution Load Management System) in the Jinwi River unit basin, and to propose a management plan by selecting the point that needs improvement of water quality in order to achieve the target water quality. We evaluated the discharge and water quality characteristics, statistical analysis, daily delivery load and daily delivery density, grade classification, for 14 total pollution load site's from 2014 to 2016 year in Jinwi river unit basin. The average discharge of Jinwi river unit basin is $22.411m^3/s$ and discharge of Hwangguji River is 32.8% and the water quality characteristics along the tributary river were clarified spatially. As the result, it was analyzed that Seongeun River is an indirect indicator of organic pollutants, Gwanri River is a seasonal factor, Osan River and Hwangguji River both affect water quality. Estimation of delivered pollutant loads at the HG-3 site was 6,470.4 BOD kg/day, 6,846.7 TN kg/day and delivered pollutant loads density increased to $220.9BOD\;kg/day/km^2$, $22.4TP\;kg/day/km^2$ at the HG-4 site. This result demonstrates that the total pollution load site needed to improve water quality of the Jinwi River unit basin was HG-3 site.

• Journal of Environmental Impact Assessment
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• v.17 no.4
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• pp.255-262
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• 2008

For the Han-river estuary and DMZ where white-naped crane (Grus vipio; endangered migratory bird) stopover or spend winter, the habitat composition and the habitat use pattern of white-naped crane were analyzed with the position data obtained by the satellite tracking method. By the use of geographic information system (GIS), the percent composition of seven habitat categories of white naped-crane data points (n=228) was analyzed. The chi-square test showed that the white-naped crane habitat use pattern was significantly different (p<0.05) from that of random points (n=228). It means that white-naped crane select and use particular habitat area in the Han-river estuary and DMZ.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.1
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• pp.19-29
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• 1991

This second stage study on the Wild and Scenic Rivers System is a proposal for system disignation. Study area is the part of the Han River flowing through the Seoul Metropolitan Region. Consequently, developpment pressure and demand for recreational land uses along the river are very high, and that is why the Wild and Scenic rivers System is urgently needed for the Han River among other major rivers of the nation. Resource inventory and assessment followed the process developed in the first stage study. Figure-4 shows the proposed Wild and Scenic Rivers System designation, Also proposed are manage-ment guidelines and legal, organizational arrangement.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.501-508
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• 2013

We have researched heterogeneity of naturalized river plant community by ${\beta}$-diversity for restoration of river community which has high diversity plant species. As a result the average of heterogeneity was 0.32(range 0.23~0.37) from the river to the inland. This value shows community turnover of species composition of plant communities 6 times. The ${\beta}$-diversity was no difference among water system of Seomjin river, Han river, Nakdong river and Geum river. The upper-river valley(0.36) was higher than lower-river valley(0.23) in each water system(p level<0.05). Multiple regressing analysis was used for look the relationship with Environmental factors as a result, it shows ${\beta}$-diversity significant on a slope. River mimetic diagram with dominant species that appear through Belt-transect painted. Dominant plant species turned 6 time in upper-river and turned about 5 time in lower-river. The result of this study suggested practical basis of planting species and planting pattern. To improve species diversity of river plant community, slope degree raise is the most important.