Toward Optimal Rainfall-Advancing Hydrologic Rainfall Estimation by Improving Soil Moisture Initialization to Close the Water Budget within Observational Uncertainty in Headwater Basins
Barros AP and Liao M. 2025. Toward Optimal Rainfall-Advancing Hydrologic Rainfall Estimation by Improving Soil Moisture Initialization to Close the Water Budget within Observational Uncertainty in Headwater Basins. SSRN
ABSTRACT: Liao and Barros (2022 and 2023) presented a new methodology to correct orographic Quantitative Precipitation Estimation (QPE) products from remote-sensing observations constrained to close the water budget at storm-flood timescales in headwater basins. They identified uncertainty in initial soil moisture conditions as a barrier to achieve water budget closure within observational uncertainty of discharge measurements, that is the golden standard in hydrological modeling. The objective of this manuscript is to address this limitation by introducing a physics-based methodology to correct soil moisture (i.e., Initial Condition Correction, ICC) in a manner consistent with the Inverse Rainfall Correction (ICC) methodology proposed by Liao and Barros (2022). The coupled IRC-ICC framework is demonstrated for 215 flood-producing events from 2008 to 2024 in28 headwater basins along the latitudinal range of the Appalachians across diverse hydroclimatic and physiographic regions. Results show a median KGE (calculated at 15-minute intervals) of 0.86 for simulated floods using the QPE corrected using new IRC-ICC framework, with peak timing errors within 60 minutes, and median error of flood volume achieving less than 2%. This study establishes the coupled IRC-ICC as a robust general framework for orographic QPE correction and provides a pathway to characterizing and modeling soil moisture uncertainty ahead of extreme precipitation events at high spatial resolution O(100m).
- Type
- Published Report
- Authors
- Barros, Ana; Liao, Mochi
- Date of Issue
- 2025
- Publisher
- SSRN
- Units
- GRSM
- Keywords
- Cataloochee Valley, flash floods, GRSM-00493, headwater basins, Initial soil moisture uncertainty, orographic precipitation errors