본 연구는 반폐쇄성 해역인 마산만을 대상으로 eco-hydrodynamic model을 이용하여 해역의 물리적 구조를 분석하여, 물리적 안정도를 나타내는 수직확산계수를 산정하고, 생태계 모델에 적용하여 그 타당성을 평가하는 것이다. 해역의 물리적 구조는 EFDC모델을 사용하여 구하였으며, 수직 확산계수는 수층간의 밀도차이가 커질수록 감소하도록 산정하였다. 산정된 수직 확산계수를 Stella프로그램을 이용하여 구축한 생태계모델에 적용하여, 용존산소 재현성으로 그 타당성을 평가하였다. 수직확산계수 변화를 추정하여 적용한 모델의 결과는 2008년의 R2값은 0.529~0.700으로 나타났으며, 2009년 R2값은 0.542~0.791로 나타났다. 계산값은 관측값과 유사한 경향을 나타내었으며, 만 내측의 빈산소수괴를 잘 재현하였다. 본 연구에서 적용된 수직확산계수는 해역의 밀도성층과 물리적 안정도를 의미하는데, 향후 폐쇄성 내만해역의 빈산소수괴 발생 예측에 유용하게 활용될 것으로 판단된다.

As forest land takes up 65% of the Korean peninsula, there have been continuing conflicts between the development and conservation of forest land. As the income level has changed over time, the usage of forest land in society has changed. There has been increasing demands for forest land for urban development and recreational use. On the other hand, a large proportion of the land is required to be preserved for the forest and the natural ecosystem in it. The existing management system for the forest land has been designed focusing on the management of the trees on the land, and not the land itself. Due to this limitation, the current management system of forest land has failed to protect the forest land from being developed indiscreetly, making it difficult to conserve and develop the forest land in an efficient way. A major question in forest land management is how to integrate economic use activities with the supporting ecosystems to maximize performance of the ecological-economic system. In order to promote sustainable use of forest resources, and to achieve efficient forest land management, it is prerequisite to evaluation on forest resources of natural ecosystems. Quantitative measures are needed that signify how necessary the services and products of forested ecosystems are to human endeavors. In this study, the natural wealth provided by forest land was quantified based on emergy synthesis. Emergy is a universal measure of real wealth of the work of nature and society made on a common basis. Thus, Calculations of emergy provide a basis for making choices about environment and economy following the general public policy to maximize real wealth. The goals of forest land management to achieve balance between the ecology and economy of its integrated system and to foster equity among the diverse outcomes of the forest land were assessed with emergy. Emergy was demonstrated to holistically integrated and quantify the interconnections of a coupled nature-human system allowing the goals of ecological balance and outcome equity to be measured quantitatively. Doing so will provide a better understanding of the basis of forest land wealth and the consequences of management decisions.

A macroeconomic minimodel was simulated to suggest the public policy for sustainable use of Nakdong River Basin. The minimodel for the simulation shows the interrelationships between natural environment and economic activity. Topsoil, water, economic assets, and money stock are plotted for 300 years, beginning with 1996 in each simulation. The computer simulation runs suggest that the Nakdong River Basin system in the near future may strongly be influenced by the favorable availability of outside resources, while the economic assets and money stock may be declined by indigenous environmental stock depletion. The simulation run made under the constant decrease in systems purchased inputs with investment ratio of developed country and for sustainable use. The results of simulation shows the recover of natural environment and decrease of economic activity under these condition. Therefore, the economic structure of Nakdong River Basin should be transformed from the present industrial structure to the social-economic structure based on an ecological-recycling concept which depend on renewable resources rather than industrial structural which depend on outside resources.

A macroeconomic minimodel was simulated to analyze the effect of global exchange on the Korea's economy. The simulation results illustrate some of the consequences of public policy and some insight into current world problems. All computer simulation runs made under various conditions suggest that the Korea's system in the near future may be strongly influenced by the favorable availability of outside resources, while the national power and assets may be declined by indigenous environmental stock depletion. The borrowed capital allows the temporary money stock to increase and the national assets to grow faster and a little higher, as using up the environmental resources more quickly. Later, when the debt is paid off, the foreign exchange holdings may not go so high. For the environmentally sound and sustainable development, over 75% of total economic production should be invested to the natural resource management. Therefore, the economic structure of Korea should be transferred from the present industrial structure to social-economic structure based on ecological-recycling concept.

The conflicts between environment protection and economic development are becoming increasingly important in environmental decision making of Nakdong River Basin. A science-based evaluation system is now needed to represent both the environmental values and the economic values with a common measure. EMERGY, spelled with an "m" evaluates both the work of river and that of human in generating products and services. The monetary cost-benefit analysis and the environmental accounting by EMERGY analysis were applied to determine whether there will have a net benefit in environmental decision making of Nakdong River Basin. Based on the results of the environmental accounting, all alternatives which related to environmental decision making of Nakdong River Basin show that more and more of EMERGY cost becomes needed than the EMERGY benefit from getting water to drink in the lower basin. From these results, for selecting alternatives to manage water quantity and quality that is sustainable in the environmental use and economic development, environmental accounting concepts must be considered, and the economic structure of Nakdong River Basin should be changed from the present industrial structure to social-economic structure based on ecological-recycling concept for the sustainable use of Nakdong River.

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(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 is 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.