• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.115-126
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• 2015

In recent years, debris flow disaster has occurred in multiple locations between high and low mountainous areas simultaneously with a flooding disaster in urban areas caused by heavy and torrential rainfall due to the changing global climate and environment. As a result, these disasters frequently lead to large-scale destruction of infrastructures or individual properties and cause psychological harm or human death. In order to mitigate these disasters more effectively, it is necessary to investigate what causes the damage with an integrated model of both disasters at once. The objectives of this study are to analyze the mechanism of debris flow for real basin, to determine the PMP and run-off discharge due to the DAD analysis, and to estimate the influence range of debris flow for fan area according to the scenario. To analyse the characteristics of debris flow at the real basin, the parameters such as the deposition pattern, deposit thickness, approaching velocity, occurrence of sediment volume and travel length are estimated from DAD analysis. As a results, the peak time precipitation is estimated by 135 mm/hr as torrential rainfall and maximum total amount of rainfall is estimated by 544 mm as typhoon related rainfall.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.824-827
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• 2011

Needs for Smart Grid development are increasing all over the world as a solution to its problem according to depletion of energy resources, climatic and environmental rapidly change and growing demand for electrical power. Especially decentralized power is attracting world's attention. In this mood a new era for a unit scale of decentralized power environment is on its way in building. However there is a problem to have to be solved in the uniformity of power quality because the amount of power generated from renewable energy resources such as wind power and solar light is very sensitive to climate fluctuation. And thus this paper tries to suggest an energy management algorithm on basis of real time monitoring for meteorological data. The proposed EMS model embodies the method for predicting the power generation by monitoring and analyzing the climatic data and controling the efficient power distribution between the renewable energy and the existing power. The ultimate goal of this paper is to provide the technological basis for achieving zero-energy house.

• Environmental and Resource Economics Review
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• v.20 no.4
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• pp.827-858
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• 2011

In Korea, various environmentally harmful subsidies are granted in agriculture, fishery, energy, electricity, transportation, steel and shipbuilding industry. Examples include tax-exempt fuel for agriculture & fishery, VAT- exemption for briquette & anthracite, temporary subsidy for fuel, production stabilizing subsidy for coal mining, subsidy for briquette. Korea's yearly total subsidy in energy area is about 5,291 billion won, among them is 4,870 billion won. To reduce air pollutants and to mitigate climate change, Korea has to review the phase-out of environmentally harmful subsidies and the phase-in of environment-friendly subsidy. The reduction or removal of environmentally harmful subsidies will enhance economic efficiency and bring about environmental benefits. Economic efficiency means less use of inputs, which reduces environmental cost and improves social benefits. This paper applies the Shoven and Whalley's model to the Korean economy and analyzes the general equilibrium incidence effects of reforming environmentally harmful subsidies in the energy and electricity in Korea. We consider several counterfactual scenarios in which current environmentally harmful subsidies are reduced or abolished, compare them with the reference case in the economy, and evaluated the change in efficiency costs and distributional incidence of tax reforms related to subsidies.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.399-420
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• 2018

This study has attempted environmental economic analysis on the cost structure of offshore fisheries based on fishery management data published by the Fisheries Research Institute to examine the effect of the environmental policy on the fisheries for the effective implementation of the Paris Convention. Under the assumption that both fisheries and carbon dioxide are simultaneously produced, the cost structure of offshore fisheries were analyzed. Cost function in a translog form was estimated and SUR (Seemingly Unrelated Regression) model was used for the analysis. Here, $CO_2$ emission of offshore fishery was calculated by using National Federation of Fisheries Cooperatives' data on supply of tax exemption oil (2003~2016). The cost function estimation showed that there is a weak disposition between catches and $CO_2$ emissions during the sample period, and the marginal abatement cost (MAC) is estimated at 1,457 won per year. In addition, for the same period, when 1% of $CO_2$ per horsepower is to be reduced MAC increases by 2.2%, and when 1% of $CO_2$ per 1 ton of catch is to be reduced, MAC increases by 1.4%.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.710-716
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• 2013

New and renewable energy sources have drawn attention because of climate change. Many studies have been carried out in waste-to-energy field. Fast pyrolysis of waste lignocelluosic biomass is one of the waste-to-energy technologies. Bubbling fluidized bed (BFB) reactor is widely used for fast pyrolysis of the biomass. In BFB pyrolyzer, bubble behavior influences on the chemical reaction. Accordingly, in the present study, hydrodynamic characteristics and fast pyrolysis reaction of waste lignocellulosic biomass occurring in a BFB pyrolyzer are scrutinized. The computational fluid dynamics (CFD) simulation of the fast pyrolysis reactor is carried out by using Eulerian-Granular approach. And two-stage semi-global kinetics is applied for modeling the fast pyrolysis reaction of waste lignocellulosic biomass. To summarize, generation and ascendant motion of bubbles in the bed affect particle behavior. Thus biomass particles are well mixed with hot sand and consequent rapid heat transfer occurs from sand to biomass particles. As a result, primary reaction is observed throughout the bed. And reaction rate of tar formation is the highest. Consequently, tar accounts for 66wt.% of the product gas. However, secondary reaction occurs mostly in the freeboard. Therefore, it is considered that bubble behavior and particle motions hardly influences on the secondary reaction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.871-874
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• 2010

Needs for Smart Grid development are increasing all over the world as a solution to its problem according to depletion of energy resources, climatic and environmental rapidly change and growing demand for electrical power. Especially decentralized power is attracting world's attention. In this mood a new era for a unit scale of decentralized power environment is on its way in building. However there is a problem to have to be solved in the uniformity of power quality because the amount of power generated from renewable energy resources such as wind power and solar light is very sensitive to climate fluctuation. And thus this paper tries to suggest an energy management method on basis of real time monitoring for meteorological data. In the current situation of lacking in USN-based killer application in Smart Grid field, this paper proposes the USN-based DER management system which collects the meteorological data and control power system througout utilizing wireless sensor network technique this business. This communication technique is regarded to be efficient in aspects of installation cost and tits maintenance cost. The proposed EMS model embodies the method for predicting the power generation by monitoring and analyzing the climatic data and controling the efficient power distribution between the renewable energy and the existing power. The ultimate goal of this paper is to provide the technological basis for achieving zero-energy house.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.692-698
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• 2001

This study has been carried out to estimate aboveground biomass and net primary production(NPP) in an average 41-years-old Quercus variabilis stand of Gongju area, 45-years-old Quercus variabilis stand of Pohang area, and 54-years-old Quercus variabilis stand of Yangyang area. Ten sample trees were cut in each forest and soil samples were collected in July to August, 2000. Estimation for aboveground biomass and net primary production were made by the equation model $Wt=aD^b$ where Wt is oven dry weight in kg and D is DBH in cm. Total aboveground biomass was 91.31ton/ha in Gongju area, 207.6ton/ha in Pohang area, and 71.39ton/ha in Yangyang area. The aboveground biomass 207.6ton/ha in Pohang area is the highest biomass production among the amount of biomass in Quercus variabils stands reported in Korea. The proportion of each tree component to total aboveground biomass was high in order of bolewood, bolebark, branches and leaves in the three forests. Aboveground total net primary production was estimated at 7.8ton/ha in Gongju area, 11.5ton/ha in Pohang area, and 6.40ton/ha in Yangyang area. There were at least 2 times higher total aboveground biomass in Pohang area than in the Gongju and Yangyang areas because of climate difference among the study areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.232-232
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• 2019

The persistence of drought periods and water scarcity is a growing public concern, as climate change projections indicate a more critical scenario in the future. The sustainability of water resources for the increasing population, and to ensuring crop production will unarguably be a daunting task for the water resources managers, with a projected 9.8 billion people by 2050 as well as the need to increase food production by 70 to 100%. Consequently, there is a need for significant irrigation water use for more crop production in the face of stiff competition among water users. However, the available natural resources are already over-constrained, and the allocation of more resources for food production is not feasible. Currently, about two-thirds of global water withdrawer is used by the agricultural sector while 48% of water resources in Korea is used for agricultural production. Despite the apparent ecological deficit and unfavorable conditions of resources utilization, a staggering amount of food waste occurs in the country. Moreover, wastage of food translates to waste of all the resources involved in the food production including water resources. Food waste can also be considered a serious potential for economic and environmental problems. Hence, exploring an alternative approach to efficient resources utilization in a more sustainable way can ensure considerable resources conservation. We hypothesized that reducing food waste will decline the demand for food production and consequently reduce the pressure on water resources. We investigated the food wastage across the food supply chain using the top-down datasets based on the FAO mass balance model. Furthermore, the water footprint of the estimated food wastage was assessed using the representative of selected food crops. The study revealed that the average annual food wastage across the food supply chain is 9.05 million tonnes, signifying 0.51 kg/capita/day and 48% of domestic food production. Similarly, an average of 6.29 Gm3 per annum of water resources was lost to food wastage, which translates to 40% of the total allotted water resources for agriculture in the country. These considerable resources could have been conserved or efficiently used for other purposes. This study demonstrated that zero food waste generation would significantly reduce the impact on freshwater resources and ensure its conservation. There is a need for further investigation on the food waste study using the bottom-up approach, specifically at the consumer food waste, since the top-down approach is based on estimations and many assumptions were made.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.408-408
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• 2019

The persistence of drought periods and water scarcity is a growing public concern, as climate change projections indicate a more critical scenario in the future. The sustainability of water resources for the increasing population, and to ensuring crop production will unarguably be a daunting task for the water resources managers, with a projected 9.8 billion people by 2050 as well as the need to increase food production by 70 to 100%. Consequently, there is a need for significant irrigation water use for more crop production in the face of stiff competition among water users. However, the available natural resources are already over-constrained, and the allocation of more resources for food production is not feasible. Currently, about two-thirds of global water withdrawer is used by the agricultural sector while 48% of water resources in Korea is used for agricultural production. Despite the apparent ecological deficit and unfavorable conditions of resources utilization, a staggering amount of food waste occurs in the country. Moreover, wastage of food translates to waste of all the resources involved in the food production including water resources. Food waste can also be considered a serious potential for economic and environmental problems. Hence, exploring an alternative approach to efficient resources utilization in a more sustainable way can ensure considerable resources conservation. We hypothesized that reducing food waste will decline the demand for food production and consequently reduce the pressure on water resources. We investigated the food wastage across the food supply chain using the top-down datasets based on the FAO mass balance model. Furthermore, the water footprint of the estimated food wastage was assessed using the representative of selected food crops. The study revealed that the average annual food wastage across the food supply chain is 9.05 million tonnes, signifying 0.51 kg/capita/day and 48% of domestic food production. Similarly, an average of $6.29Gm^3$ per annum of water resources was lost to food wastage, which translates to 40% of the total allotted water resources for agriculture in the country. These considerable resources could have been conserved or efficiently used for other purposes. This study demonstrated that zero food waste generation would significantly reduce the impact on freshwater resources and ensure its conservation. There is a need for further investigation on the food waste study using the bottom-up approach, specifically at the consumer food waste, since the top-down approach is based on estimations and many assumptions were made.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.417-418
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• 2018

미국 국립가뭄경감센터 (National Drought Mitigation Center, NDMC)는 다양한 가뭄지수를 통합하여 미국 전역의 가뭄진행상황을 모니터링하고 가뭄대응정책 수립을 위한 주요 의사결정정보로 활용하고 있다. 대표적으로 1999년에 개발되어 현재까지 운영 중인 미국가뭄모니터 (United States Drought Monitor, USDM)는 미국 전역에 대하여 가뭄단계를 표시한 지도 (U.S. Drought Monitor map)를 매주 생성하여 제공하고 있다 (http://droughtmonitor.unl.edu/). 가뭄지표(drought index)는 가뭄의 현황과 시공간적인 전개 과정을 분석하고 정량적 가뭄심도 평가 및 가뭄대응계획 수립을 위한 도구로써 다양하게 개발되어 활용되고 있다. 가뭄의 정도를 정량화하기 위하여 개발된 다수의 가뭄지수는 대상과 평가방법에 따라 가뭄을 표현하는 특성이 서로 다르다. 하나의 가뭄지수로는 가뭄특성을 온전히 표현하기 어렵기 때문에, 최근에는 단일 가뭄지수에 의존하기 보다는 다수의 가뭄지수를 이용하되, 여러 가뭄지수 간의 특징을 고려하여 각 가뭄지수가 갖는 장단점을 상호 보완하여 사용하기를 권고하고 있다. USDM은 파머가뭄심도지수 (Palmer Drought Severity Index, PDSI), Soil Moisture Model (NOAA Climate Prediction Center, CPC), 미 지리조사국의 하천유량 주간보고 (USGS Weekly Streamflow), 표준강수지수 (Standardized Precipitation Index, SPI) 등의 주요 가뭄판단지표를 선정하고, 가뭄판단의 기준으로써 각 가뭄지수의 가뭄심도 (drought severity) 및 백분위수 (percentiles)로 등급을 구분하였다. 가뭄등급은 '정상 상태 (none)'를 포함하여 '비정상적인 건조 (abnormally dry, D0)'에서 최악의 가뭄상태를 의미하는 '이례적인 가뭄상태 (exceptional, D4)'에 이르는 6 단계로 구분하고, 정상상태를 제외한 5 단계의 통합가뭄단계로 표시한다. 우리나라에서는 기상청, 수자원공사, 농어촌공사에서 기상/수문/농업관련 가뭄지수의 위험지도를 실시간으로 제공하고 있으며, 각 지표별로 상이한 기준으로 가뭄을 판단하고 있다. 각각의 가뭄지표에 대한 가뭄판단기준은 해당 국가의 장기적으로 축적된 자료를 활용하여 가뭄단계 및 가뭄판단기준의 재설정에 대한 연구가 필요하다. 본 연구에서는 SPI, SC-PDSI, 표준강수증발산지수 (Standardized Precipitation Evapotranspiration Index, SPEI), Evaporative Demand Drought Index (EDDI), 유효가뭄지수 (Effectvie Drought Index, EDI)의 다양한 가뭄지수를 활용하여 USDM의 가뭄심도 및 가뭄판단기준을 적용하고자한다.