Estimating future streamflow under climate and land use change conditions in northeastern Hokkaido, Japan

Study region: Abashiri River, northeastern Hokkaido, Japan.Study focus: In response to the growing concern over likely future climate and land use land cover (LULC) changes, a better understanding of the consequent streamflow changes is needed in northeastern Hokkaido, Japan. The present study focuses on the Abashiri River Basin (ARB), northeastern Hokkaido, and estimates the future local streamflow and its change in quantity, seasonality, flow regime, and spatial distribution under various possible impacts of climate and LULC conditions. The estimation is produced using the Soil and Water Assessment Tool (SWAT), a hydrological model suitable for managemental analysis. Future conditions are applied as alter-ations to the initial model inputs.New hydrological insights for the region: Possible impact of climate change leads to significant changes in streamflow quantity and flow pattern around the snowmelt season, while negative and insignificant change in streamflow is expected in response to possible LULC change. The results highlight a concerning future for local agricultural water use. Consequently, practical recom-mendations for local water resources management are advised, focusing on precautionary mea-sures and development insights. Compared to existing research in this region, the present study provides a comprehensive estimation of the possible future streamflow changes on a finer spatiotemporal scale. Further application in the future to help the local water resources man-agement is expected.