Evaluation of Socioeconomic Effect for Sabo Works

Case Study in the Hirakawa River, Nagano Prefecture in Central Japan

Abstract

Many sabo works have been provided in the Hirakawa River, Nagano prefecture in Central Japan. These sabo works have led to prevent occurring debris disasters leaving human lives and properties, as the socioeconomic effect thereof. This study dealt with the Hirakawa River, as a case study area to evaluate the socioeconomic effect.
The study conducted in 1985, estimated the total cost (C) of these sabo works in 1947 to 1985 at 7, 083 million yen. The direct benefit of the prevention to debris disasters (B₁) is estimated to be 15, 867 million yen, the indirect benefit of that (B₂), 952 million yen, the enhanced land use benefit (B₃), 16, 258 million yen, and the amenity benefit (B₄), 360 million yen. The ratio B 1/C of 2.24 and B (B₁+B₂+B₃+B₄)/C of 4.72 were derived from the study.