Disentangling slope-scale spatial variability of saturated hydraulic conductivity in the black soil region of northeast China using noise-assisted multivariate empirical mode decomposition

Yang Yang, Tingting Peng, Hui Zhang, Ole Wendroth, Zixin Jin, Xinyi Chen, Yingna Liu

Research output: Contribution to journalArticlepeer-review

Abstract

Reliable estimates of saturated hydraulic conductivity (Ks) are usually difficult to obtain, as Ks is regulated by a variety of soil processes acting at different spatial scales that may obscure each other's impacts. We hypothesized that these scale-specific relationships could be well characterized with the aid of the noise-assisted multivariate empirical mode decomposition (NA-MEMD), thereby serving as a solid foundation for an accurate Ks prediction. The objective was to evaluate whether the incorporation of NA-MEMD could improve the estimation of Ks based on the multiscale associations it unraveled. On a typical slope transect of 860 m in the black soil region of northeast China, Ks, mollic epipedon thickness, bulk density, soil organic carbon content, total (ϕ) and effective porosities (ϕe), and particle size distribution were investigated at every 20 m. Prior to NA-MEMD, Ks was most strongly correlated with ϕe, and the linear regression models based on ϕe solely were satisfactory for Ks estimation at the scale of investigation. Adding other predictors significantly improved Ks prediction in calibration, but impaired it in validation. Upon decomposition by NA-MEMD, Ks was found to be significantly associated with each attribute at two scales of oscillation at least. Summing up the estimates of each Ks component derived from the properties at the equivalent oscillation scales, the results outperformed the traditional multiple linear regressions made at the investigation scale, when the same sets of predictors were used. The application of NA-MEMD, moreover, could save the tedious measurements of ϕe and ϕ. Excluding these two porosity-related properties, Ks estimates obtained by incorporating NA-MEMD were statistically similar or even better than those involving them before NA-MEMD. These findings demonstrate the great potential of NA-MEMD in untangling scale-dependent relationships of Ks with various processes and hold important implications for future estimations of Ks and other hydraulic properties in the black soil region of northeast China and similar regions.

Original languageEnglish
JournalVadose Zone Journal
DOIs
StateAccepted/In press - 2024

Bibliographical note

Publisher Copyright:
© 2024 The Authors. Vadose Zone Journal published by Wiley Periodicals LLC on behalf of Soil Science Society of America.

ASJC Scopus subject areas

  • Soil Science

Fingerprint

Dive into the research topics of 'Disentangling slope-scale spatial variability of saturated hydraulic conductivity in the black soil region of northeast China using noise-assisted multivariate empirical mode decomposition'. Together they form a unique fingerprint.

Cite this