• Korean System Dynamics Review
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• v.11 no.1
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• pp.27-57
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• 2010

This article deals with an ecological-economic analysis of the 'Pasture Project of Kum River', which is the farming plan of mitten crabs using Jichun, a stream of the River Kum where the natural propagation of mitten crabs are blocked because of the estuary dam constructed in 1990. Toward analyzing the ecological and economic effects of the crab releasing and harvesting activities in Jichun, a two-stage cohort model of population dynamics with cannibalistic behaviors and density restrictions in biomathematics is adopted, despite of the current infertility in Kum, considering the opportunity of establishing dam fishways in the near future. This study moreover presents a method of parameter estimation especially with assuming a steady state of the ecosystem, and performs various analyses such as the risk measurement of climate change and the economic value of such fishways.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.2
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• pp.40-54
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• 2008

Small and large dams are installed in the course of a stream for maintaining the water level of the stream or obtaining agricultural water. Currently about 18,000 of them are installed in Korea to supply water. However, the environmental problems of small dams are well known : the interruption of stream eco-corridors, deterioration of water quality in the upper reaches of the small dam, changes in the habitats of riparian organisms, damages to the stream scenery. In a very few of these small dams artificial eco-corridors like fishways are installed, but the number is very minimal.Accordingly, to efficiently restore stream eco-corridors by removing these small dams, it will be necessary to closely examine physical impacts, such as changes in the riverbed and changes in the shape of the stream caused by the removal, chemical impacts, such as changes in water quality, and transport and accumulation of contaminated sediments and biological impacts, such as changes in the habitats of organisms, and develop related technologies in advance, and have these technologies verified through demonstration application in the sites. In this study, we analyzed the physical, chemical and ecological impacts of the removal of the above-mentioned small dams, and conducted a research on the demonstration small dam removal project for a spot investigation. As a result, the small dam removal will restore the eco-corridor, there by improving the habitat of fishes and crustaceans. The number of major underwater organisms inhabiting the Gokreungcheon, such as Korean spotted sleepers, Chinese minnows, Microphysogobio yaluensis, Abbottina rivularis, stone morokos, striped shinners, long-nosed barbels, and Chinese mitten crabs, is expected to increase, and the food chain in the ecosystem will improve so that species diversity will improve as well.