Soil moisture responses to rainfall: Implications for runoff generation

  • Authors: Singh, Nitin K.; Emanuel, Ryan E.; McGlynn, Brian L.; Miniat, Chelcy F.
  • Publication Year: 2021
  • Publication Series: Scientific Journal (JRNL)
  • Source: Water Resources Research, 57: e2020WR028827.
  • DOI: 10.1029/2020WR028827

Abstract

Soil moisture is a key control on runoff generation and biogeochemical processes on hillslopes. Precipitation events can evoke different soil moisture responses with depth through the soil profile, and responses can differ among landscape positions along a hillslope. We sought to elucidate the nature of these responses by estimating changes in water content, response time between peak precipitation and peak soil moisture, and wetting front velocities for 43 storms at 45 locations on three adjacent hillslopes within a headwater catchment of the southern Appalachian Mountains (NC, USA). We used a multivariate modeling approach to quantify the relative influences and the predictability of soil moisture responses by a combination of landscape and storm characteristics. We quantified the lag correlations between hillslope mean soil moisture and catchment runoff to demonstrate how storm properties and hillslope-scale characteristics may influence runoff at the catchment outlet. Soil moisture responses varied widely, and no consistent patterns were observed among response metrics laterally or vertically along hillslopes. In contrast to other studies, we found that the relative influence of hillslope properties and storm characteristics varied with soil moisture responses and during storms. Antecedent conditions and storm depths influenced the strength of lag correlations between soil moisture and runoff, whereas storm mean intensity was correlated with the lag times. These results highlight the utility of intensive observations for characterizing heterogeneity in soil moisture responses, suggesting, among other things, a need for better representation of the subsurface processes in rainfall-runoff models. Identifying the relative importance of drivers can be beneficial in building parsimonious hydrological models.

  • Citation: Singh, Nitin K.; Emanuel, Ryan E.; McGlynn, Brian L.; Miniat, Chelcy F. 2021. Soil moisture responses to rainfall: Implications for runoff generation. Water Resources Research, 57: e2020WR028827.
  • Keywords: soil moisture, rainfall, runoff generation, hillslopes
  • Posted Date: September 17, 2021
  • Modified Date: September 25, 2021
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • To view this article, download the latest version of Adobe Acrobat Reader.