森林の荒廃による表面流出の発生および細粒土砂の河川への流出(<小特集>水環境)

概要

論文の詳細を見る
To assess the fluvial sediment sources in unmanaged Japanese cypress plantation watersheds, in which one has skid trail networks and the other without skid trail, field measurements and fingerprinting suspended sediment were conducted in the Shimanto River basin, southern Japan. The observation of erosion and runoff processes were conducted by using runoff plot and integrated suspended sediment samplers for 5 months. For fingerprinting of suspended sediment, ^<137>Cs and ^<210>Pb_<ex> were determined by gamma-ray spectrometry for the potential source materials as the surface soil of forest floor, stream bank and skid trail, the mobilized sediment by splash and overland flow, and suspended sediment in stream channel. The contribution of forest floor to suspended sediment estimated by ^<137>Cs can be as high as c.a. < 50% and < 96% for the catchment with skid trail networks and the catchment without skid trail, respectively. These results indicate that forest floor should be recognized as important source of fluvial sediment in this watershed.
社団法人地盤工学会の論文
2007-08-01