ABSTRACT:

This data product is related to a journal article by Chuqiang Chen and Admin Husic entitled "Streamflow composition in U.S. rivers is shifting toward recent precipitation".

Abstract:
The fraction of streamflow derived from recent precipitation—'event water’—profoundly impacts water quality and flood risk. We show that over the past four decades, this fraction has significantly increased in 27% of 754 U.S. catchments. We achieved the first continental-scale reconstruction by applying a deep learning model to a novel tracer dataset spanning nearly 24,000 storm events. Using explainability methods, we attribute intensifying precipitation, urbanization, and deforestation as the primary drivers. Event water fraction increases nearly two times more frequently than streamflow increases, indicating that for many rivers where streamflow trends are stationary, the composition of streamflow is changing. These results reveal a widespread shift towards the rapid conversion of precipitation to streamflow by watersheds, signaling a need to adapt water management strategies for a future of accelerating climate and land-use pressures.