Reconciling the Attribution of Changes in Streamflow Extremes From a Hydroclimate Perspective

Abstract

AbstractWith increasing impacts of climate change and human interventions on the hydrological cycle, attributions of changes in streamflow and its extremes were widely carried out to provide guidelines for adaptation. However, most of them neglected either human‐induced climate or hydrological change. Here we propose a reconciled framework to attribute influences from anthropogenic and natural climate change, land cover change and human water withdrawal. A set of 45 years high‐resolution (0.01°) land surface hydrological simulations were conducted over a semiarid river basin in North China, forced by changing climate and/or land cover scenarios. There are discernible anthropogenic climate change fingerprints on the changes in annual mean streamflow and wet extremes (ratio of wet months), while land cover change and water withdrawal are more important for the change in dry extremes (ratio of dry months). The impact of human‐induced hydroclimate change on streamflow extremes could be underestimated by up to 21–59% or 12–43% based on hydrological or climate attribution alone, suggesting the necessity of the reconciled framework for distinguishing different anthropogenic factors.