抄録
Previous study focused on the water yield changes at the outlet of the catchments for the thinning or clear-cut managements. However, how the water yield pattern will change spatially after forest thinning practice was yet to be clarified. This study was conducted in a small forested catchment in Iizuka, Fukuoka Prefecture, about 3ha and with steep terrain. The study site was thinned 50% of the planted vegetation and its effects will be studied. Streamflow generation mechanism can be affected by the catchment vegetation despite of the strong influence of topography and belowground environment. In the study watershed, the relative size of water yield pattern changed before and after forest thinning. We studied the streamflow generation mechanism by measuring hillslope groundwater table, riparian groundwater table, soil moisture in relation to stream flow across the watershed to clarify the factor controlling this spatial water yield pattern change before and after thinning.
