Connecting Hydraulic Property Scaling Factors to Spatial Patterns of Soil Water Flux Measurements.

Linear scaling theory (e.g., Miller-Miller scaling or Warrick-Nielsen scaling) is often used to account for the spatial variability of soil hydraulic properties and is the basis for Sposito’s work investigating the scale-invariance of the Richards equation.  Linear scaling theory, however, is not appropriate for all soils.  Furthermore, the calculation of scaling factors usually involves labour-intensive measurement of hydraulic properties on a large number of samples.  Field measurements of soil water content and potential, while relatively difficult to acquire, are more commonly collected.  With new technology available such as wireless sensors, it will soon be common place to have very large, spatially explicit datasets of soil water content which can potential be used to calculate local soil water fluxes.  The primary objective of this research is to quantify the relationship (if any)  between the spatial patterns of soil water flux (as would be measured by commonly available instrumentation – TDR) and underlying assumptions about the nature and distribution of soil hydraulic property scaling factors.  Preliminary investigations are carried out with Hydrus2D simulations.