🤖 AI Summary
This study addresses the challenge that existing rainfall intensity models struggle to simultaneously maintain mathematical consistency—such as non-crossing return periods across time scales—and parameter parsimony when applied across multiple temporal resolutions (from minutes to weeks). Moreover, most models are confined to seasonal extremes and lack the ability to characterize the full distribution of rainfall intensities. To overcome these limitations, this work proposes a parsimonious multiscale statistical framework based on the extended generalized Pareto distribution (EGPD), uniquely integrating EGPD with rainfall aggregation processes. By leveraging Poisson compounding and Panjer recursion, the method enables efficient likelihood-based inference. With only eight parameters, it consistently models rainfall intensity distributions from 6 minutes to 3 days, ensures naturally ordered return periods, and supports reliable sub-annual scale estimation. Validation at six climatically diverse sites in France demonstrates that the resulting IDF curves are cross-scale consistent, parameter-efficient, and computationally tractable.