Spatial Distribution Patterns of Clean Water System based on GIS Spatial Analysis in the Nakdong River basin of South Korea : Focused on Indicator Species

摘要

The objectives of this study are to identify the spatial distribution of clean water system in the Nakdong River basin of South Korea and to provide useful information for efficient national conservation and restoration policy in aquatic ecosystem. The clean water system was evaluated using indicator species(Achnanthe convergens) and the spatial analyses including Kriging, Local statistics and Local Moran's I were used to identify the degree of spatial dependence on water quality and riparian environment parameters for 250 sites in the Nakdong River basin(parameters: BOD, Chl-a, T-P, T-N, NH3-N, N03-N, P04-P, Natural Sand Bar, Natural River Channel, Diversity of Velocity, Streamside Width, Riparian, Levee Material, Sediment Condition, Transverse Structure, Riverside Land Use and Inundation Area Use). As a result, indicator species was discovered in 170 spatial points out of 250, and the creatures in N004, N006, N011, N013, N052, N086, N164 points were occupied more than 50 percent of all species. And it had showed a high inhabitation density at the upper region of Nakdong River, Geumho River, Miryang River, and Hapcheon Dam. Also, indicator species tend to live in high-dense points in Riverside Land Use, Riparian, Sediment Condition and Natural River Channel, whereas Transverse Structure, Streamside Width, Diversity of Velocity, Natural Sand Bar, Inundation Area and Streamside Width did not affect the creature's environment. Therefore, the clean water systems were mostly distributed in low BOD, T-P, P04-P, NH3-N, Chl-a and were tended to distribute in high-dense points in Riverside Land Use, Riparian, Sediment Condition and Natural River Channel in the Nakdong River basin. Sites of clean water system were evaluated as best or normal by aquatic ecosystem health assessment. In conclusion, the spatial features of indicator species will be used as a base data for aquatic ecosystem and environment preservation policies.