Seminar: Jiaxin Xie
Institutsseminar
- Datum: 04.04.2024
- Uhrzeit: 14:00
- Vortragende(r): Jiaxin Xie
- (Reichstein department)
- Raum: Hörsaal (C0.001)
Large global groundwater recharge inferred from streamflow observations
The proportion of streamflow that comes from groundwater remains
highly uncertain. Previous estimates of this proportion were 86% (land
surface model) or less than 28% (latest IPCC report). We compiled daily
streamflow observations in 15,567 global watersheds to derive a
bottom-up estimate of this proportion. Implications for groundwater
simulation are as follows:
- Groundwater sustains 59% ± 7% of global streamflow, narrowing the wide range of Earth system model simulations (12% to 94%).
- At least 21% ± 3% of precipitation recharges groundwater, which is twice the recharge rate estimated in the IPCC AR6 report, suggesting a much more active role of groundwater in the water cycle than most models and global water cycle diagrams currently present.
- Soil emerges as the largest contributor to observational spatial variations in streamflow proportions from groundwater, while most Earth system models identify precipitation as the primary driver.