• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.439-445
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• 2010

An emergy analysis of the main energy flows driving the economy of humans and life support systems consists of environmental energies, fuels, and imports, all expressed as solar emjoules. Total emergy use (371 E20 sej/yr) of the Western Nakdong River Basin is 97 per cent from imported sources, fuels and goods and services. Emergy flows from the environment such as rain and geological uplift flux accounted for only 2.9 percent of total emergy use. Emergy yield ratio and environment loading ratio were 1.03 and 33.27, respectively. Emergy sustainability index, a ratio of emergy yield ratio to environment loading ratio, is therefore less than one, which is indicative of highly developed consumer oriented economies. It is necessary for an efficient management of Western Nakdong River Basin to reduce pollution load basically and to restructure economic activities into an environmental friendly industrial structure depending on renewable energy and resources.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.35-43
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• 2014

The purpose of this study is to analyze emergy flows of rice for evaluating the value of rice production and sustainability. Emergy analysis evaluates the sustainability of systems or processes considering all the inputs to make a product or a sevice. In this study, we analyzed the emergy flows and indices of rice productionand compared the regional emergy values using statisticcal analysis: input materials, hours per unit area(10a), and production costs. As the results, we found that the rates of external investment (EIR= 18.87) and environmental loading (ELR=21.7) are significantly high during the rice cultivation. However, emergy yield ratio(EYR) shows that rice is a valuable resource because EYR is 5.12 and environmental Sustainability IndexSI value is as low as 0.24 and it shows rice has low sustainability. This study also shows that Chungcheongnam-do has the highest SI value for rice production due to low environmental loading and abundant natural energy during rice cultivation. These results of rice emergy flows and sustainability assessments could provide a way of sustainable rice cultivation with decrease of environmental loading from fertilizer.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.1087-1099
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• 2017

Emergy methodology was used to analyze the biophysical basis of Korean agriculture and assess its sustainablility. Total yearly emergy input into Korean agriculture was $7.72{\times}10^{22}sej/yr$ in 2013. Purchased inputs were the dominant emergy source, accounting for 90.1% ($6.95{\times}10^{22}sej/yr$) of the annual input. This clearly indicates that the Korean agriculture is a modern, industrialized system that depends mostly on market goods and services derived from nonrenewable resources. The monetary equivalent of the total emergy input was 18.9 trillion \/yr, 1.5 times greater than the total production cost from farm expense surveys. Emergy return on investment of Korean agriculture was low, with an emergy yield ratio of 1.11. Korean agriculture appears to exert pressure on the environment as revealed by the high environmental loading ratio of 9.30. With very low emergy input from renewable sources (9.7%) and high environmental pressure, Korean agriculture is not sustainable, with an emergy sustainability index of 0.12. This study suggests that higher use efficiency of and lower dependence on nonrenewable purchased inputs need to be prioritized in an effort to enhance the sustainability of Korean agriculture.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.482-496
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• 2023

Many changes in the scale and structure of the Korean rice cropping system have been made over the past few decades. Still, insufficient research has been conducted on the sustainability of this system. This study analyzed changes in the Korean rice cropping system's sustainability from a system ecology perspective using an emergy approach. For this purpose, an emergy table was created for the Korean rice cropping system in 2011, 2016, and 202, and an emergy-based indicator analysis was performed. The emergy analysis showed that the total emergy input to the rice cropping system decreased from 10,744E+18 sej year^-1 to 8,342E+18 sej year^-1 due to decreases in paddy field areas from 2011 to 2021, and the proportion of renewable resources decreased by 1.4%. The emergy input per area (ha) was found to have decreased from 13.13E+15 sej ha^-1 year^-1 in 2011 to 11.89E+15 sej ha^-1 year^-1 in 2021, and the leading cause was a decrease in nitrogen fertilizer usage and working hours. The amount of emergy used to grow 1 g of rice stayed the same between 2016 and 2021 (specific emergy: 13.3E+09 sej g^-1), but the sustainability of the rice cropping system (emergy sustainability index, ESI) continued to decrease (2011: 0.107, 2016: 0.088, and 2021: 0.086). This study provides quantitative information on the emergy input structure and characteristics of Korean rice cropping systems. The results of this study can be used as a valuable reference in establishing measures to improve the ecological sustainability of the Korean rice cropping system.

• Journal of Environmental Science International
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• v.9 no.6
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• pp.449-454
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• 2000

Sustainable development has been the key concept, both in economic policies and in environmental management. On the basis of an systems ecology perspective, this suggests the sustainable development of Korea\`s natural environment and economic activity using the EMERGY evaluation. The total EMERGY use(7,730E20sej/yr) in Korea is 81 percent from imported sources, fuels and goods and services. The ratio of outside investment to attracting natural resources is already large, like other industrialized countries. Continued availability of purchased inputs at a favorable balance of EMERGY trade, currently about 2.85 to 1 net EMERGY, tis the basis for present economic activity and must decrease as the net EMERGY of purchased inputs including fossil fuels goes down. EMERGY yield ratio and environmental loading ratio were 1.23 and 20.30, respectively. The population level is already in excess of carrying capacity. Its carrying capacity for steady state on its renewable sources is only 2.2 million people, compared to 45.9 million in 1977. EMERGY sustainability index is therefore less than one, which is indicative of highly developed consumer oriented economies. Until now the development of a country has been achieved by the economic growth, but it can be sustained in the long run by the use of renewable resource systems. the efficiency of energy usage, and the transformation of the social-economic structure based on an ecological-recycling concept.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_1
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• pp.1-10
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• 2001

An emergy evaluation of the natural environment ant economy of Seoul revealed that Seoul used 1.27 E23 sej/yr of emergy in 1997. The emergy input from the Han River accounted for most of the renewable emergy sources. Emergy imported from foreign countries and other parts of Korea accounted for 97% of the total emergy use in Seoul in 1997, revealing that the economy of Seoul is more dependent on outside emergy sources than for the entire Korean economy. The emergy use per unit area(2.09 E14 sej/$m^2$/yr) was higher than that for the entire country or Pusan, whereas the emergy use per capita(1.22 E16 sej/person/yr) was lower than that for the entire country or Pusan. These results reflect the overcrowded conditions in Seoul where about one fourth of the Korean population now live. They also seem to indicate a lower living standard in Seoul than the average in Korea. The quality of living in Seoul could also be judged by a high environmental loading ratio and a low sustainability index. All there indices suggest that people in Seoul live under a higher environmental stress than the average person in Korea.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.49-55
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• 2000

An EMERGY analysis of the main energy flows driving the economy of humans and life support systems consists of environmental energies, fuels, and imports, all expresses as solar emjoules. Total EMERGY use(720.0 E20 sej/yr) of the Nakdong River Basin is 96 per cent from imported sources, fuels and goods and services. EMERGY flows from the environment such as rain and geological uplift flux accounted for only 4 percent of total EMERGY use. Consequently, the ratio of outside investment to attracting natural resources was large, like other industrialized areas. EMERGY use per person in the Nakdong River Basin indicates a moderate EMERGY standard of living, even though the indigenous resources are very poor. Population of 6.66 million people in 1996 is already in excess of carrying capacity of the basin. Carrying capacity for steady state based on its renewable sources in only 0.226 million people. EMERGY yield ratio and environment loading ratio were 1.07 and 28.52, respectively. EMERGY sustainability index, a ratio of EMERGY yield ratio to environment loading ratio, is therefore less than one, which is indicative of highly developed consumer oriented economies. This study suggests that the economic structure of the Nakdong River Basin should be transformed from the present industrial structure to the social-economic structure based on an ecological-recycling concept for the sustainable use of the Nakdong River.

• Journal of Environmental Impact Assessment
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• v.25 no.2
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• pp.141-154
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• 2016

This study was conducted laying the focus on finding the mutual action between the substantial ecological value and economic system in the national land, and calculating the environmental carrying capacity and sustainability of the national land using the emergy synthesis. Particularly, this study pays attention watchfully to the reality that the analytic framework to analyze sustainability is not arranged well, as the concept of sustainable development considering environmental carrying capacity, which becomes a widely discussed topic today, is defined differently according to the subjective views of respective researchers, and the situation which needs in-depth evaluation on the interaction between nature and economy which becomes the fundamental of sustainable development. This study also aims at groping for correct direction for the national land development by calculating the environmental carrying capacity and index value which is appropriate to the national land and providing the framework for preparing the policy to induce the sustainable use and management of the national land. The concept of emergy synthesis which is used for the evaluation of environmental carrying capacity and sustainability in the national land, as in this case, can notify the information on current situation of the national land as well as explain how the national land transforms according to time pass (the role of information synthesis), and gives knowledge if the national land policies advances toward the direction of sustainable development (the role of policy evaluation and observation). Emergy synthesis also can take role for selecting best policy on the process of decision making on the exploitation of the national land (the role on the process of decision making).

• Journal of Environmental Science International
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• v.22 no.4
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• pp.507-514
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• 2013

The Nakdong River being used as drinking water sources for the Busan metropolitan city has the vulnerability of water management due to the fact that industrial areas are located in the upper Nakdong River. This study used emergy analysis method to evaluate ecological-economics of water treatment systems of D water treatment plant (WTP) where located in the downstream of the Nakdong River. The emergy methodology is a system evaluation tool that uses energy as the common currency to compare different resources on a common basis. Emergy yield ratio (EYR) and emergy sustainability index (EmSI) of D WTP were 1.16 and 0.18, respectively. It means not resources and sustainable system but consumer goods and not sustainable system. Ratio of emergy benefit to the purchaser (EBP) shows 2.7 times higher than economic costs. To change the weak water source and situations we need to diversity water intake.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.185-191
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• 2000

Sustainable development has been the key concept, both in economic policies and in environmental management since 1970s. In the view of systems ecology, sustainable resource use strategies are considered to be essential in achieving sustainable development. During the last three decades, the discipline of systems ecology has applied ecological energetic analysis to the evaluation of the contribution of natural environments to economic systems. ENERGY analysis of main energy flows driving the economy of humans and life support systems of a city was made including environmental energies, fuel, and inputs, all expressed as solar emjoules. Total EMERGY use of Pusan was 3.89 E22 sej/yr, about 90 percent of it was purchased sources from outside during eleven years from 1985 to 1995. EMERGY flows from the environment were less than 10 percent. EMERGY yield ratio and environmental loading ratio were 1.10 and 10.45, respectively. EMERGY sustainability index is there(ore less than one, which is indicative of highly developed consumer oriented economies. Development of a city has been achieved in the short run by the economic growth, but it can be sustained in the long run by the use of renewable resource systems.