• Journal of Environmental Policy
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• v.9 no.2
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• pp.3-19
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• 2010

Anyang-cheon(stream) runs through southern metropolitan area of Seoul to Han-river in Korea. Due to fast growth of Seoul, the water quality and quantity problems in Anyang-cheon have occurred. To cope with the problems, the Integrated Watershed Management program for Anyang-cheon was adopted and a KRW 26.1 billion (USD 21.8 million) pilot project (construction of 4 facilities such as reservoir) is suggested for 4 sub-watersheds of Anyang-cheon, which cost will be shared by the 12 local governments (LG). Three cost division schemes are compared. By Scheme 1, if the cost is borne by the LG in a watershed where the facilities are constructed (no cost division scheme), the LG in I is to bear 0.58% of the total construction cost, LG in watershed II 29.54%, LG in IV 0%, LG in V 69.88%. In particular, LG in IV in this scheme bears no cost because no facility is constructed, even though watershed IV is the major beneficiary of the facility construction. Scheme 2 is to share the cost by length of streams in each sub-watershed and the suggested cost share for each sub-watershed is 13.76% by I, 7.34% by II, 45.87% by IV, and 33.03% by V. However, this cost division scheme is fair only under the false assumption that the bargaining powers of group of LGs are identical. To suggest a better and fair division rule, Shapley Value, a cooperative game solution, is used to suggest Scheme 3. In Scheme 3, Shapley Value measures the summation of average marginal contribution of each player in all possible coalitions as cost division scheme and is known to provide a fair division considering bargaining power. In the context of Anyang-cheon, LGs in upper stream have superior bargaining position. The result suggests the cost division is fair under Scheme 3, when the cost shares are 0.29% by I, 14.77% by II, 50% by IV, and 34.94% by V, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.567-577
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• 2015

Climate and land use changes have impact on availability water resource by hydrologic cycle change. The purpose of this study is to evaluate the hydrologic behavior by the future potential climate and land use changes in Anseongcheon watershed ($371.1km^2$) using SWAT model. For climate change scenario, the HadGEM-RA (the Hadley Centre Global Environment Model version 3-Regional Atmosphere model) RCP (Representative Concentration Pathway) 4.5 and 8.5 emission scenarios from Korea Meteorological Administration (KMA) were used. The mean temperature increased up to $4.2^{\circ}C$ and the precipitation showed maximum 21.2% increase for 2080s RCP 8.5 scenario comparing with the baseline (1990-2010). For the land use change scenario, the Conservation of Land Use its Effects at Small regional extent (CLUE-s) model was applied for 3 scenarios (logarithmic, linear, exponential) according to urban growth. The 2100 urban area of the watershed was predicted by 9.4%, 20.7%, and 35% respectively for each scenario. As the climate change impact, the evapotranspiration (ET) and streamflow (ST) showed maximum change of 20.6% in 2080s RCP 8.5 and 25.7% in 2080s RCP 4.5 respectively. As the land use change impact, the ET and ST showed maximum change of 3.7% in 2080s logarithmic and 2.9% in 2080s linear urban growth respectively. By the both climate and land use change impacts, the ET and ST changed 19.2% in 2040s RCP 8.5 and exponential scenarios and 36.1% in 2080s RCP 4.5 and linear scenarios respectively. The results of the research are expected to understand the changing water resources of watershed quantitatively by hydrological environment condition change in the future.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.345-352
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• 2017

The average global temperature on Earth has increased by about $0.85^{\circ}C$ since 1880 due to the global warming. The temperature increase affects hydrologic phenomenon and so the world has been suffered from natural disasters such as floods and droughts. Therefore, especially, in the aspect of water deficit, we may require the accurate prediction of water demand considering the uncertainty of climate in order to establish water resources planning and to ensure safe water supply for the future. To do this, the study evaluated future water balance and water deficit under the climate change for Anseong river basin in Korea. The future rainfall was simulated using RCP 8.5 climate change scenario and the runoff was estimated through the SLURP model which is a semi-distributed rainfall-runoff model for the basin. Scenario and network for the water balance analysis in sub-basins of Anseong river basin were established through K-WEAP model. And the water demand for the future was estimated by the linear regression equation using amounts of water uses(domestic water use, industrial water use, and agricultural water use) calculated by historical data (1965 to 2011). As the result of water balance analysis, we confirmed that the domestic and industrial water uses will be increased in the future because of population growth, rapid urbanization, and climate change due to global warming. However, the agricultural water use will be gradually decreased. Totally, we had shown that the water deficit problem will be critical in the future in Anseong river basin. Therefore, as the case study, we suggested two alternatives of pumping station construction and restriction of water use for solving the water deficit problem in the basin.

• Journal of Korea Water Resources Association
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• v.38 no.4 s.153
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• pp.301-311
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• 2005

The purpose of this study is to assess the quantitative effect of stream discharge due to land use changes. The upstream watershed of Pyeongtaek gauging station of Anseong-cheon ($592.6\;km^2$) was adopted. To accomplish the purpose, firstly, trace land use changes for the selected watershed which have some changes of land use by using Landsat images of 1986 and 1999 of the watershed and secondly, analyse the quantitative effect of stream discharge due to land use changes by applying GIS- based distributed hydrologic model KIMSTORM. The model was calibrated and verified at 2 locations (Pyeongtaek and Gongdo) by comparing observed with simulated discharge results for 7 storm events from 1998 to 2003. Model output was designed to provide information of land use impact on runoff components in the watershed and the sensitivity of impact level of each land use category on storm runoff. Land use impact was evaluated with the land use data sets for 1986 and 1999 for the same rainfall condition (160.5 mm). Area decrease of 4.8 percent of forest and 4.0 percent of paddy field during 13 years (1986 - 1999) within the watershed caused a 30.3 percent increase of peak runoff and a 9.3 percent increase of runoff volume.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.155-165
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• 2010

In low-lying districts of urban areas, pump stations were built to protect flooding by the heavy rain. Particularly, the automatic pump operation system was installed for efficiency in the pump stations of Seoul. However, the effective pump operation is difficult under existing operating system because the system only performs operation by reservoir depth. This study would like to improve the real time operating system suggested by Jun et al.(2007) and to apply the system Gasan 1 pump station in Seoul. For various design rainfall events, maximum water levels simulated by the suggested system were 10~70cm lower than results by the existing system. And overflow volume at upstream manholes were 50% reduced. We converted the flood control effects by establishment of the suggested system to economic indicators. To obtain the same effect, approximately 4.9 billion won needs to expand pump capacities or 3.2~6.9 hundreds million won needs to construct storm water detention on upstream area. The suggested system could improve the flood control stability by efficient operation of the existing pump station.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.1
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• pp.56-70
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• 2017

In this study, multi-image information for the central Taewha River basin was used to develop and analyze a distribution map of non-point pollution sources. The data were collected using a hyper-sensor (image), aerial photography, and a field spectro-radiometer. An image correction process was performed for each image to develop an ortho-image. In addition, the spectra from the field spectro-radiometer measurements were analyzed for each classification to create land cover and distribution maps of non-point pollutant sources. In the western region of the Taewha River basin, where most of the forest and agricultural land is distributed, the distribution map showed generated loads for BOD($kg/km^2{\times}day$) of 1.0 - 2.3, for TN($kg/km^2{\times}day$) of 0.06 - 9.44, and for TP($kg/km^2{\times}day$) of 0.03 - 0.24, which were low load distributions. In the eastern region where urbanization is in progress, the BOD, TN, and TP were 85.9, 13.69, and 2.76, respectively and these showed relatively high load distributions when the land use was classified by plot.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.509-516
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• 2020

Since the 1960s, many rivers have been polluted and destroyed due to river repair projects for economic development and the covering of small rivers due to urbanization. Many studies have analyzed rivers using measured river topographic factors, but surveying is not easy when the flow rate changes rapidly, such as during a flood. In addition, the previous research has been mainly about the cross section of a river, so information on the longitudinal profile is insufficient. This research used informational entropy theory to obtain an equation that can calculate the average river slope, river slope, and river longitudinal elevation for a river basin in real time. The applicability was analyzed through comparison with measured data of a river's characteristic factors obtained from a river plan. The parameters were calculated using informational entropy theory, nonlinear regression analysis, and actual data. The longitudinal elevation entropy equation for each stream was then calculated, and so was the average river slope. All of the values were over 0.96, so it seems that reliable results can be obtained when calculating river characteristic factors.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.1
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• pp.58-66
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• 2014

Water pollution problems of urban rivers due to the urbanization and industrialization have been the subject of public attention. In particular, considering the fact that the characteristics of water cycle of each basin change dramatically through the development of new towns, a large number of concerns about future water quality have been raised. However, reasonable measures to predict future water quality quantitatively have not been presented by this moment. In this study, by the linkage of annual unit load generation based on long-term monitoring results of the ministry of environment (MOE) to a semi-distributed rainfall runoff model, SWMM (Storm Water Management Model), we proposed a new methodology to estimate future water quality macroscopically and testified it to verify its applicability for the estimation of future water quality of a small watershed at G new town. As a result of the estimation using Y-EMC (Yearly based Event Mean Concentration), future water quality were simulated as BOD 18.7, T-N 16.1 and T-P 0.85 mg/L respectively which could not achieve the grade III of domestic river life guidance and these criteria could be satisfied by the reduction of domestic wastewater discharge load by over 80%. The results of this study are shown to be utilized for one of basic tools to estimate and manage water quality of urban rivers in the course of new town developments.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.11-19
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• 2014

This study is analyze future climate and land cover change affects behaviors for amount of streamflow and sediment discharge within basin. We used the climate forecast data in RCP 4.5 and 8.5 (2011-2100) which is opposite view for each other among RCP scenarios that are discussed for 5th report for IPCC. Land cover map built based on a social economic storyline in RCP 4.5/8.5 using Logistic Regression model. In this study we set three scenarios: one scenario for climate change only, one for land cover change only, one for Last both climate change and land cover change. It simulated amount of streamflow and sediment discharge and the result showed a very definite change in the seasonal variation both of them. For climate change, spring and winter increased the amount of streamflow while summer and fall decreased them. Sediment showed the same pattern of change steamflow. Land cover change increases the amount of streamflow while it decreases the amount of sediment discharge, which is believed to be caused by increase of impervious Surface due to urbanization. Although land cover change less affects the amount of streamflow than climate change, it may maximize problems related to the amount of streamflow caused by climate change. Therefore, it's required to address potential influence from climate change for effective water resource management and prepare suitable measurement for water resource.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.467-475
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• 2015

The Deokjin Pond is one of the places representing Jeonju City's history but has the poor water quality. The pond has a storage of $88,741m^3$ and a drainage area of $3.77km^2$. It has been maintained only by the groundwater pumped from the upstream wells and the direct rainfalls on the water surface since the old streams replenishing the pond were turned into a part of the sewer system due to indiscreet urbanization. The lack of replenishing water as well as the organic-rich bottom sediment were suggested as two main causes deteriorating the water-ecosystem. In this study, possible measures obtaining waters for restoration of Deokjin Pond ecosystem are discussed. It is estimated that the present pond can be replenished about 32 times a year by the runoff when the drainage system in the watershed is recovered to a state before urbanization. To support this, the drainage system is compared with that of nearby Osong Pond, which shows relatively better water-ecosystem. Even though Osong Pond has a drainage area one-seventh of that of Deokjin Pond, its storage is more than the half of it. It is because its watershed has a near natural drainage system where the rain mostly infiltrates into soil and slowly discharges into the pond. Therefore, it is believed that the low impact development (LID), which is known as a technique restoring the water circulating system to a condition before development, would be helpful in obtaining waters required for Deokjin Pond ecosystem management.