Abstract
In Okinawa Island, the nature restoration project with the river improvement is essential to the river environmental regeneration, which induces the restoration of ecosystem in river and brackish water region. The results of water quality survey, river fish investigation and potential analysis of river environmental activity are employed and analyzed to classify and evaluate 61 rivers in Okinawa Island for the nature restoration planning. The water quality survey for DO, turbidity, T-N and T-P represents the evaluation of pollution load from the catchment area and the information of fish habitats, for the influence of river structures. The analysis revealed the priority of the nature restoration project among 61 rivers in Okinawa Island. The rivers in central region of Okinawa Island are found to have high priority on the nature restoration project.
