Fig. 1.

Observed departure of salt-affected basins from the classic Budyko’s framework. (A) Classification of world drainage basins by average level of salinization (${\hat{\mu }}_{C,i}$) based on salinity data from the HWSD (34). (B and C) Australian sub-basins categorized by salinization level (B) and hydro-climatic forcing $\gamma$ (C; Results and Discussion, Observed Partitioning in Saline River Basins and ref. 35). (D and E) Observed terrestrial water balance of unaffected (D) and salt-affected (E) sub-basins of Australia. Catchment-scale evaporative fraction, $⟨ET⟩/⟨R⟩$, and dryness index, $D_I$, are inferred from AWAP data (Materials and Methods; dots) and contrasted with the theoretical Budyko’s curves obtained via the stochastic water-balance method introduced by Porporato et al., 2004 (P04; ref. 36). The P04’s theoretical curves do not account for salinity effects on hydrological partitioning.