• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.26-38
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• 2006

For both a healthy environment and sustainable development, we frame a habitat assessment method, concerning biodiversity and physical characteristics. With the method, we set up and extract conservation areas from Peace Valley Resort Development Areas which can function as habitats. Absolute and relative assessment items which are the size of area, habitation of species with conservation value, distribution of communities, functions of habitats, ratio of non-native plants, connectivity of habitats, vegetation layers of forests and age of forests, and water systems are considered on newly extracted conservation areas, and the habitat value assessment was calculated on the items in a 3-point scale. By comparing and examining 3 existing proposals for extracted conservation areas, we assess existing proposals, make an alternative proposal, and try to verify the possibility of applicability to extracted conservation areas. Proposal A and C must not be adopted since almost all conservation areas would be developed in the proposals. Proposal B, consisting of 53% development areas and 47% non-development areas, does not have enough development areas, so high density building arrangements should be encouraged in order to preserve conservation areas. Therefore, proposal B would be the best in ecological terms among the 3 proposals, if 3 conditions are considered : 1) new extracted conservation areas should be conserved; 2) 10~15m wide green-zones on both sides of the water system, which can play a role as ecological corridors, should be considered in development areas; 3) building arrangement should not interrupt the ecological corridors.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.772-776
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• 2008

The Korea Electric Power Research Institute (KEPRI) has been developing planar solid oxide fuel cells (SOFCs) and power systems for combined heat and power (CHP) units. The R&D work includes solid oxide fuel cell (SOFC) materials investigation, design and fabrication of single cells and stacks, and kW class SOFC CHP system development. Anode supported cells composed of Ni-YSZ/FL/YSZ/LSCF were enlarged up to $15{\times}15\;cm^2$ and stacks were manufactured using $10{\times}10\;cm^2$ cells and metallic interconnects such as ferritic stainless steel. The first-generation system had a 37-cell stack and an autothermal reformer for use with city gas. The system showed maximum stack power of about $1.3\;kW_{e,DC}$ and was able to recover heat of $0.57{\sim}1.2\;kW_{th}$ depending on loaded current by making hot water. The second-generation system was composed of an improved 48-cell stack and a prereformer (or steam reformer). The thermal management subsystem design including heat exchangers and insulators was also improved. The second-generation system was successfully operated without any external heat source. Under self-sustainable operation conditions, the stack power was about $1.3\;kW_{e,DC}$ with hydrogen and $1.2\;kW_{e,DC}$ with city. The system also recuperated heat of about $1.1\;kW_{th}$ by making hot water. Recently KEPRI manufactured a 2kW class SOFC stack and a system by scaling up the second-generation 1kW system and will develop a 5kW class CHP system by 2010.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2169-2175
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• 2009

This research aims to evaluate the concept of eco-efficient water infrastructure and provides a list of case studies in order to help understand the applicability of eco-efficient water infrastructure to Asia and the Pacific. A set of indicators have been explored to assess eco-efficiency in water infrastructure for the region on a micro and macro scale. The core idea of eco-efficiency, 'more value with less impact (on the environment)', has proven to be applicable in management of water infrastructure. The fundamental elements in eco-efficient water infrastructure should encompass physical infrastructure and non-physical infrastructure, which is more needed particularly in Asian countries. The case studies have demonstrated the applicability of the concept of eco-efficient water infrastructure. The Republic of Korea has provided the case of the eco-friendly approaches to enhance dam management and its innovative solutions how to use water more efficiently through state-of-art technologies. The experiences of Singapore are some of the best evidence to establish eco-efficient water infrastructure, for instance, the NEWater project via application of cutting edge technologies (recycled water) and institutional reform in water tariff systems to conserve water as well as enhance water quality. A list of indicators to assess eco-efficiency in water infrastructure have been discussed, and the research presents a myriad of project cases which are good to represent eco-efficiency in water infrastructure, including multipurpose small dams, customized flood defense systems, eco-efficient ground water use, and eco-efficient desalination plants. The study has presented numerous indicators in five different categories: 1) the status of water availability and infrastructure; 2) production and consumption patterns of freshwater; 3) agricultural products and sources of environmental loads; 4) damages from water-caused natural disaster; and 5) urban water supply and sanitation. There are challenges as well as benefits in such indicators, since the indicators should be applied very carefully in accordance with specific socio-economic, political and policy contexts in different countries in Asia and the Pacific Region. The key to success of establishment of eco-efficient water infrastructure in Asia primarily depends on the extent to which each country is committed to balancing its development of physical as well as non-physical water infrastructure. Particularly, it is imperative for Asian countries to transform its policy focus from physical infrastructure to non-physical infrastructure. Such shift will help lead to implementation of sustainable in Asian countries.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.37-47
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• 2009

This study analyzes the effect of alternatives and estimates alternatives evaluation index (AEI) using PCSWMM and weighted summation method. PCSWMM considering combined sewer overflows (CSOs) in the Mokgamcheon watershed was used and effectiveness analysis of alternative was conducted to develop not only flowrate but also the pollutant of BOD and SS. Indicators of AEI are selected using sustainability evaluation concept, driver-pressure-state-impact-response (DPSIR) framework and calculated by weighted summation method. After estimating AEI, alternatives was classified into three groups G (Good), A (Acceptable) and P (Poor) grade. As a results, it is analyzed that alternatives applied to Oryucheon were G grade and those of Yeokgokcheon were P grade and the remainings were 'A' grade. This result will be effective to the integrated watershed management for sustainablility.

• The Journal of Engineering Geology
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• v.25 no.3
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• pp.403-412
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• 2015

We summarize the status of exploitable groundwater reserves in Korea based on reports of the National Basic Groundwater Plan, and review methods for estimating groundwater recharge rates, as recharge is a key factor in the estimation of exploitable groundwater reserves. We also outline the various methods used to assess exploitable groundwater reserves in previous groundwater investigation reports. Regarding advancements in the estimation of exploitable groundwater, we recommend that enhanced estimation methodologies (e.g., the water balance method and the advanced water table fluctuation method) and sustainable groundwater management concepts be adopted in the near future.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.267-267
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• 2019

Driftwood is one of serious problems in a river environment. In several countries, such as Indonesia, Japan, and Italy, the driftwood frequently appears in a river basin, and it can alter the channel bed, flow configuration by wood deposition and jam formation. Therefore, the studies related to driftwood have been actively conducted by many researchers to understand the mechanism of driftwood dynamics. In particular, wood motion by collision is one of the difficult issues in the numerical simulation because the calculation for wood collision requires significantly expensive calculation time due to small time step. Thus, this study conducted the numerical simulation in consideration of the wood motion by water flow and wood collision to understand the wood dynamics in terms of computation. We used the 2D (two-dimensional) depth-averaged velocity model, Nays2DH, which is a Eulerian model to calculate the water flow on the generalized coordinate. A Lagrangian type driftwood model, which expresses the driftwood as connected sphere shape particles, was employed to Nays2DH. In addition, the present study considered root wad effect by using larger diameter for a particle at a head of driftwood. An anisotropic bed friction was considered for the sliding motion dependent on stemwise, streamwise and motion directions. We particularly considered changeable draft at each particle and projection area by an angle between stemwise and flow directions to precisely reproduce the wood motions. The simulation results were compared with experimental results to verify the model. As a result, the simulation results showed good agreement with experimental results. Through this study, it would be expected that this model is a useful tool to predict the driftwood effect in the river flow.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.93-103
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• 2018

The aim of this study is to apply the Water-Energy-Food-Land Nexus approach which can analyze the trade-offs among resources, and assess the holistic impacts of food security. First, we applied rice as a study crop and analyzed the trend of consumption of rice and the area of paddy fields. Second, the portfolios of water, energy, and land for rice production were constructed using data of footprints and productivity. Finally, the self-sufficiency ratio (SSR) of rice in target year was set as food security scenario and assessed the impacts of food security on water, energy, and land availability. In 2030, the SSR of rice decreased to 87 %, and water use for producing rice decreased from 4,728 to $3,350million\;m^3$, and the water availability index increased from 0.33 to 0.53. However, food security is essential issue and we set the 50 % and 100 % SSR of rice as high and low food security scenarios. For 100% SSR in 2030, about $3,508million\;m^3$ water was required and water availability index reached to 0.5. In other words, there is the trade-off between food security and water-energy-lands availability. Therefore, it is difficult to make a decision whether a high level of SSR is better or worse. However, this study showed the both positive and negative impacts by change of food security and it can be useful for setting the policy decision considering both food security and sustainable resource management at the same time.

• Journal of Korea Water Resources Association
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• v.41 no.5
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• pp.463-471
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• 2008

The purpose of this study is to analyze the features of groundwater use to utilize as basic information for water-cycle analysis system development and effective groundwater management in the Kap-cheon basin. The cumulative relationship between groundwater use and the number of wells was analyzed to estimate the representative total groundwater use and the number of wells for the Kap-cheon basin. Then, the spatial distribution of groundwater use in the basin were figured out using the detailed information on groundwater use in each well. Finally, the reasonability of groundwater resources management in Kap-cheon basin was evaluated by comparing groundwater recharge and groundwater use in sub-basins and major stream basins. The results of the analysis showed about 25% of the total wells could represent 90% of groundwater use ($37,923,516\;m^3$/year) in the Kap-cheon basin. A detailed analysis on the groundwater uses in the vicinity of down-town areas of Daejeon metropolitan city showed high groundwater uses ($1.4{\sim}11.1$ times) compared to the groundwater recharge previously estimated using the rainfall-runoff model. The ratio of groundwater use and groundwater recharge for the major river basins in Kap-cheon basin ranged from 1.9 to 2.3 indicating that more sustainable groundwater management should be exercised. The results of this study can be used as basic information in evaluating the change of groundwater flow, stream flow and water-cycle for various groundwater uses in the Kap-cheon basin.

• Journal of Korea Water Resources Association
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• v.55 no.7
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• pp.515-529
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• 2022

Identifying the available water resources amount is an essential process in establishing a sustainable water resources management plan. Dam facility is a major infrastructure storing and supplying water during the dry season, and the water supply yield of the dam varies depending on dam inflow conditions or operation rule. In South Korea, water supply yield of dam is calculated by reservoir simulation based on observed historical dam inflow data. However, the water supply capacity of a dam can be underestimated or overestimated depending on the existence of historical drought events during the simulation period. In this study, probabilistic inflow data was generated and used to estimate the appropriate range of the water supply yield of hydropower dams. That is, a method for estimating the probabilistic dam inflow that fluctuates according to climatic and socio-economic conditions and the range of water supply yield for hydropower dams was presented, and applied to hydropower dams located in the Han river in South Korea. It is expected that the understanding water supply yield of the hydropower dams will become more important to respond to climate change in the future, and this study will contribute to national water resources management planning by providing potential range of water supply yield of hydropower dams.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.373-377
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• 2004

Since, in 1970, diatoms and diatom indices was first used in measuring quality of streams and rivers at the Seine Water Agency in France, five other water agencies began to show interests since 1990. In 1994, associated with CEMAGREF (Centre National du Machinisme Agricole du Genie Rural et des Eaux et des Forets : environmental science and expertise for the sustainable management of land and water), the six French Water Agencies (Seine, Rhone-Mediterranee-Corse, Artois- Picardie, Loire-Bretagne, Rhin-Meuse and Adour-Garonne) developed a practical diatom index, which is liable to be used routinely in the territorial streams and rivers of whole France, and which is liable to promote and facilitate its use in monitoring water networks. In 1995, the first version of a biological diatom index (IBD) was generated by them. Since then, the software update for IBD calculation and the user's network have led to numerous practical applications in France. Furthermore, the Water Agencies have run applicable programs on the National Basin Network from 1996, and the initial data set of IBD was completed. Re- examination of the complete data set was done at the end of 1998, and the tests on different calculation options of the IBD led to a third version of this index in June,2000 (AFNOR NF T 90-354).