An empirical vegetation correction for soil water content quantification using cosmic ray probes

作者：Baatz R^*; Bogena H R; Franssen H J Hendricks; Huisman J A; Montzka C; Vereecken H

来源：Water Resources Research, 2015, 51(4): 2030-2046.

DOI：10.1002/2014WR016443

• soil water content
• cosmic ray probe
• neutron intensity
• aboveground biomass
• vegetation water content

Cosmic ray probes are an emerging technology to continuously monitor soil water content at a scale significant to land surface processes. However, the application of this method is hampered by its susceptibility to the presence of aboveground biomass. Here we present a simple empirical framework to account for moderation of fast neutrons by aboveground biomass in the calibration. The method extends the N-0-calibration function and was developed using an extensive data set from a network of 10 cosmic ray probes located in the Rur catchment, Germany. The results suggest a 0.9% reduction in fast neutron intensity per 1 kg of dry aboveground biomass per m(2) or per 2 kg of biomass water equivalent per m(2). We successfully tested the novel vegetation correction using temporary cosmic ray probe measurements along a strong gradient in biomass due to deforestation, and using the COSMIC, and the hmf method as independent soil water content retrieval algorithms. The extended N-0-calibration function was able to explain 95% of the overall variability in fast neutron intensity.

• 出版日期2015-4