Volume 54 (2001-2002) Issue 1 Pages 4-11
We estimated the soil erosion rate in a small catchment of Hinoki (Chamaecyparis obtusa Sieb.) forest using Cs-137, and compared it with the sediment accumulation rate measured by direct analysis of core samples collected at the farm dam located on the bottom of the basin. Annual soil loss was calculated to be 3.1t/ha/yr using Cs-137 distribution on the hillslope. On the other hand, the soil loss was estimated to be 12.9t/ha/yr at the shallow points of the farm dam, and 1.0-1.4t/ha/yr at the deepest points. And it is expected that Cs-137 loss express the present conditions of surface soil at each sampling site. It is concluded that Cs-137 can be used as an indicator for estimation of surface soil erosion at Japanese Hinoki forest.