2024 Volume 80 Issue 16 Article ID: 23-16186
This study evaluated the impact of population decline on stream-flow using the distributed runoff model in the three small- and medium-sized river basins in the Tohoku region, assuming changes in land use and river channel characteristics in response to the progressive stages of population decline. This study applied the Monte-Carlo simulations to create various land cover change scenarios so that the streamflow changes can be evaluated with its uncertainty. As a result, the maximum annual flow decreased by up to 1.0% due to the increase of forests and the decrease of artificial land use, induced by the population decline in the target watershed. Further, streamflow in the dry period was found to increase by up to 6.6% due to the land cover and river characteristics changes. The findings of this study will contribute to future river management in watersheds where population decline is significant.
