에머지 개념을 이용하여 영산강하구역, 섬진강하구역, 한강하구역의 자연환경과 사회경제활동을 평가하고 하구역 관리와 관련한 시사점을 제시하였다. 영산강하구역, 섬진강하구역, 한강하구역의 자연환경과 사회경제활동에 대한 에머지 평가는 대형 하천이 유입하는 환경적 특성과 주변 지역의 사회경제활동 중심으로 기능하는 경제적 특성 등 이들 하구역의 특성을 잘 보여주었다. 각 하구역으로 유입하는 주요 자연환경 에머지는 하천, 조석, 강수 등 이었다. 그러나 이들 재생가능에머지가 세 하구역의 전체 에머지 유입량에서 차지하는 비율은 8% 미만으로 아주 적었다. 이에 비해 하구역의 외부에서 구입하여 지역경제에 투입하는 에머지의 비율은 92~98%로 대부분을 차지하였다. 단위면적당 에머지사용량, 인구수용력, 환경부하비율, 에머지지속성지수 등 다양한 에머지 지수가 현재 영산강하구역, 섬진강하구역, 한강하구역에서 이루어지고 있는 사회경제활동의 지속성이 아주 낮다는 것을 보여주었다. 영산강하구역, 섬진강하구역, 낙동강하구역의 자연환경이 우리 경제에 기여하는 가치는 729~2,206만 Em/ha/yr으로 높게 평가되었다. 이는 우리나라 전체평균보다 2배 이상 높은 것인데, 하구역의 자연환경이 가지고 있는 생태경제적 중요성을 반영한다. 따라서 각 하구역이 가지고 있는 생태적 경제적 잠재력을 유지하고 회복하기 위한 하구환경관리정책의 수립 시행이 시급하다고 할 수 있다. 이는 인구 및 경제 집중의 완화, 하구의 환경수용력을 고려한 이용 개발 등 하구환경에 압력에 미치는 부정적 영향을 줄이기 위한 수요조절 측면의 정책과 훼손된 생태계의 복원, 인공생태계의 조성 등 생태계의 구조와기능을 회복하여 우리가 이용할 수 있는 생태계 서비스를 증가시키는 공급조절 측면의 두 가지 방향으로 추진할 필요가 있다.

유역 변경을 통한 수자원 확보방안으로 추진되고 있는 소규모 저류댐 건설에 대한 평가를 사례로 들어 자연 환경의 개발 계획에 대한 비용-편익 분석에 에머 지(Emergy)라고 하는 새로운 개념을 적용하였다. 에머지 개념은 환경 자원들이 우리 경제의 진정한 부에 기여하는 바를 평가하려는 시도이다. 에머지 평가를 위한 모델들은 시스템의 네트워크 특성들을 특별한 기호들을 이용하여 전체적으로 보여주는 모델링 언어인 에너지 시스템 언어(Energy Systems Language)를 이용하여 작성하였다. 제안된 댐 건설이 가져오는 대부분의 에머지 편익은 이 댐의 건설 목적인 용수 공급에 있었다. 댐의 건설로 형성될 호수의 생산성 증가로 인한 에머지 편익은 0.01% 미만으로 미미하였다. 주요 에머지 비용은 댐 건설비용 (28.2%), 유지관리비용 (27.2%), 사회적 혼란(22%), 수몰민의 이주비용(12.5%) 등으로 나타났다. 에머지 산출비율(Emergy yield ratio)은 퇴적물의 손실이 포함되지 않았을 경우 1.06, 퇴적물의 손실 포함되었을 경우 1.02로 나타나, 제안된 댐 건설의 순산출(Net yield) 은 그리 크지 않았다. 전통적인 비용-편익 분석 방법에 의한 비용-편익비(1.62)와 비교하여 볼 때, 에머지 개념을 이용한 비용-편익 평가에서는 제안된 댐의 편익이 낮게 나타났다. 이러한 에머지 산출비율은 생물종에 포함된 높은 에머지 때문에 시스템의 경계내에서 댐의 건설로 희귀 생물종의 손실이 일어난다면 1.0 미만으로 나타날 것이다. 이 경우 댐의 건설이 초래하는 에머지 비용은 에머지 편익보다 더 크게 될 것이다. 본 연구는 환경 자원이 감소하는 현 시점에 있어서 환경의 보다 나은 관리라는 측면에서 개발 계획들의 영향을 평가하는 데 적용될 수 있는 새로운 방법론을 소개하였다.

Emergy methodology was used to analyze the biophysical basis of Korean agriculture and assess its sustainablility. Total yearly emergy input into Korean agriculture was 7.72×10²² sej/yr in 2013. Purchased inputs were the dominant emergy source, accounting for 90.1% (6.95×10²² 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.

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.

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.

Solid wastes are among the most pressing environmental and resource concerns in Korea. The Korean government has been implementing various management alternatives to reduce the production of solid wastes and recover valuable resources from them. Refuse-derived fuel (RDF) manufacturing facilities are one of projects that aim at recovering energy from solid wastes. This study used the emergy evaluation procedure to assess the feasibility of an RDF manufacturing facility in Wonju, Korea. By converting 10,442.6 tons of combustible solid wastes into 5,801 tons of solid fuel in 2007, this facility prevented the loss of useful resources with an emergy quantity of 3.70 × 1019 sej/yr. This amounted to a potential worth of 7.04 billion emW/yr. Total emergy input required to produce 5,801 tons of RDF was 5.91 × 1019 sej/ yr with an emvalue of 11.3 billion emW/yr. The Wonju RDF manufacturing facility contributed more to the Korean economy beyond its investment cost as revealed by the emergy yield ratio of 2.67. Direct emergy benefits and costs of the RDF facility were calculated as 1.20 × 1010 emW/yr and 3.31 × 109 emW/yr, respectively, resulting in the net emergy benefit/cost ratio of 2.62. This indicates that the RDF facility was a feasible option for managing solid wastes for the city of Wonju in Korea. This study demonstrated the usefulness of the emergy concept and methodology in evaluating management alternatives for solid wastes in Korea.

This research outlines a new method for evaluation of shellfish production in Gamak Bay based on the concept of EMERGY. Better understanding of those environmental factors influencing oyster production and the management of oyster stocks requires the ability to assess the real value of environmental sources such as solar energy, river, tide, wave, wind, and other physical mechanisms. In this research, EMERGY flows from environment sources were 76% for shellfish aquaculture in Gamak Bay. EMERGY yield ratio, Environmental Loading Ratio, and Sustainability Index were 4.26, 0.31 and 13.89, respectively. Using the Emergy evaluation data, the predicted maximum shellfish aquaculture production in Gamak Bay and the FDA (Food and Drug Administration, U.S.) designated area in Gamak Bay were 10,845 ton/y and 7,548 ton/yr, respectively. Since the predicted shellfish production was approximately 1.3 times more than produced shellfish production in 2005, the carrying capacity of Gamak Bay is estimated to be 1.3 times more than the present oyster production.

The emergy concept was used to valuate the contributions of a tidal flat ecosystem included in the fourth stage reclamation plan for the Youngsan River area to the Korean economy. Emergy contributions of the ecosystem were compared with those of economic valuations performed on the same ecosystem. The tidal flat ecosystem contributed 3.55 million Em\/ha annually. This, however, cannot be compared directly with those of the economic valuations because both methodologies approach the valuation of ecosystems in different perspectives. The emergy methodology is a donor-based valuation in which what goes into making a product or service is measured, while the economic valuation is a receiver-based approach in which human receivers determine the value of an ecosystem product or service. An emergy valuation was conducted for the three ecosystem functions included in the economic valuations to compare the results of both methodologies on the same basis. Fishery production and pollutants removal contributed 9.86 million Em\/ha/yr and 0.88 million Em\/ha/yr, respective1y. The conservation value of the tidal flat ecosystem was 3.55 million Em\/ha/yr. Overall, the emergy valuation that try to include works of both human and nature on the same basis resulted in higher economic contribution of the tidal flat ecosystem than that calculated by the economic methodologies in which only human works are measured based on the willingness-to-pay of people. This study showed that the emergy concept could provide an alternative tool for policy decision-making regarding utilization and conservation of ecosystems by approaching the ecosystem valuation from a different perspective than that of economic methodologies.

The cost of the construction and management of new apartment buildings was evaluated using a monetary analysis and an emergy concept to provide a new perspective regarding the housing policy of Korea. The systems of analyses were typical apartment buildings with an area of 76.03㎡ per household in Korea built on the same size of land area. Three apartment buildings with different stories were evaluated and compared; 5-story, 15-story, and 20-story apartment buildings. The durable years of those apartments were assumed to be 40 years. The total cost of the construction and management of an apartment building was divided into three categories of construction, land purchase, and management. A 20-story apartment showed the highest cost and a 15-story apartment the lowest in the monetary cost analysis. In contrast, the emergy evaluation revealed a different pattern in the cost of construction and management, the cost increasing from a 5-story apartment to a 20-story one. This means that the higher the apartment constructed, the greater the cost in terms of real wealth. This result suggests that new evaluation methodologies like the emergy analysis should be used together with the monetary analysis to provide better insights on the national housing policy.