New metrics for characterizing and comparing soil moisture dynamics across depths and locations
| Authors: | Menberu B. Meles, Scott Raulerson, Benjamin Rau, Mashrekur Rahman, C. Rhett Jackson |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Northern Research Station |
| DOI: | https://doi.org/10.3389/frwa.2026.1840091 |
| Source: | Frontiers in Water |
Abstract
Soil moisture dynamics play a crucial role in hydrological and agroecological processes, yet currently, there are few viable statistical procedures readily available to compare soil moisture time series data from multiple locations or soil horizons. We introduce three novel soil moisture time series signatures to characterize and compare soil moisture dynamics across depths and locations: (1) recession slope, (2) slope reversal frequency, and (3) soil moisture flashiness index. We calculated two recession slopes, one between saturation and field capacity and a second between field capacity and wilting point. We applied these metrics to in-situ soil moisture data taken at different depths and locations within five experimental watersheds across the United States varying in climate and vegetation. Results show that recession slopes generally decrease with depth, with surface layers exhibiting 2–3 times steeper recessions than deeper layers. Slope reversal frequency and flashiness also decrease with depth, reflecting the damping of wetting fronts. Flashiness was strongly tied to climate and showed inter-annual variability. These signatures effectively capture the integrated effects of climate, soil properties, and landscape position on soil moisture dynamics. Our findings demonstrate the potential of these metrics for improving landscape characterization, drought prediction, and understanding of hydrological and ecological processes across diverse environments.