CONSTRUCTION OF FISH SPECIES DISTRIBUTION MODELS FOR CLASS A RIVERS AND DEVELOPMENT OF THE SYSTEM FOR SUPPORTING NATURE-ORIENTED RIVER WORK

Abstract

The system for supporting nature-oriented river work was developed for administrative agencies to perceive the distribution of fish species and necessary considerations to conserve or to recreate its habitat in advance to construction works such as river improvements. Distribution maps for 40 fish species, which include primary freshwater fish inhabit the Chikugo and the Onga River systems together with ayu (Plecoglossus altivelis) and Japanese eel (Anguilla japonica), were developed by constructing distribution models for each species by logistic regression analysis based on known habitats and environmental variables such as landscape and land use. Furthermore, options of environmental consideration in construction works for the habitat conservations or recreations were organized in charts. Those outcomes are applied to the Web-based GIS system based on the GSI maps (issued by the Geospatial Information Authority of Japan) which could be browsed with simple operation.