Revisiting large-scale interception patterns constrained by a synthesis of global experimental data

[摘要] Rainfall interception loss remains one of the most uncertain fluxes in the global water balance, hindering water management in forested regions andprecluding an accurate formulation in climate models. Here, a synthesis of interception loss data from past field experiments conducted worldwide isperformed, resulting in a meta-analysis comprising 166 forest sites and 17 agricultural plots. This meta-analysis is used to constrain a globalprocess-based model driven by satellite-observed vegetation dynamics, potential evaporation and precipitation. The model considers sub-gridheterogeneity and vegetation dynamics and formulates rainfall interception for tall and short vegetation separately. A global, 40-year(1980–2019), 0.1 ∘  spatial resolution, daily temporal resolution dataset is created, analysed and validated against in situ data. Thevalidation shows a good consistency between the modelled interception and field observations over tall vegetation, both in terms of correlations andbias. While an underestimation is found in short vegetation, the degree to which it responds to in situ representativeness errors and difficultiesinherent to the measurement of interception in short vegetated ecosystems is unclear. Global estimates are compared to existing datasets, showingoverall comparable patterns. According to our findings, global interception averages to 73.81  mm yr −1 or10.96  ×  10 3   km 3  yr −1 , accounting for 10.53 % of continental rainfall and approximately 14.06 % of terrestrialevaporation. The seasonal variability of interception follows the annual cycle of canopy cover, precipitation, and atmospheric demand forwater. Tropical rainforests show low intra-annual vegetation variability, and seasonal patterns are dictated by rainfall. Interception shows astrong variance among vegetation types and biomes, supported by both the modelling and the meta-analysis of field data. The global synthesis offield observations and the new global interception dataset will serve as a benchmark for future investigations and facilitate large-scalehydrological and climate research.

[学科分类] 妇产科学