Volcanic eruptions can cause spatiotemporal changes in the topography and ground surface infiltration capacity of basins around volcanoes, owing to the intermittent supply of pyroclastic material. Therefore, understanding the sediment production, runoff, flooding, deposition areas, type of sediment transport process, and topographical changes in basins is important to appropriately mitigate the debris flow disasters caused by rainfalls after ash deposition. In this study, we estimated the spatial distribution of the sediment production and deposition area for about one year of a basin, where pyroclastic materials were supplied continuously in the upper basin of the Arimura River in Sakurajima, Japan, using the LiDAR (Light Detection And Ranging) data. Additionally, for the active areas of sediment production, the landform of the target sub-basins was classified by geomorphic species and micro-landforms, and the type of sediment production process were estimated, and then the volume of sediment production was analyzed. The results revealed that the sub-basin located in the volcanic mountainsides (where pyroclastic cones were distributed) showed large sediment production due to headward erosion and lateral and downward erosions associated with the formation and development of new gullies. In the adjacent sub-basin with steep valley-side slopes and large valley topography, there were more active sediment production as slope failure and by gully formation and development. In the sub-basin located at the lowest part of the basin, there were active sediment production mainly in the gullies and radial valleys. Thus, in the basin, the spatial distribution of the sediment production area and the active sediment production process showed different characteristics depending on the corresponding geomorphic species and micro-landforms in each sub-basin.