estimateSoilMoistureState: A very simple estimation of soil moisture state based on...

In sharpshootR: A Soil Survey Toolkit

A very simple estimation of soil moisture state based on volumetric water content

Description

This is a very simple classification of volumetric water content (VWC) into 5 "moisture states", based on an interpretation of water retention thresholds. Classification is performed using VWC at satiation, field capacity (typically 1/3 bar suction), permanent wilting point (typically 15 bar suction), and water surplus in mm. The inputs to this function are closely aligned with the assumptions and output from hydromad::hydromad(sma = 'bucket', ...).

Soil moisture classification rules are as follows:

• VWC <= pwp: "very dry"

• VWC > pwp AND <= (mid-point between fc and pwp): "dry"

• VWC > (mid-point between fc and pwp) AND <= fc: "moist"

• VWC > fc: "very moist"

• VWC > fc AND U (surplus) > 4mm: "wet"

Usage

estimateSoilMoistureState(
  VWC,
  U,
  sat,
  fc,
  pwp,
  style = c("default", "newhall")
)

Arguments

VWC	vector of volumetric water content (VWC), range is 0-1
U	vector of surplus water (mm)
sat	satiation water content, range is 0-1
fc	field capacity water content, range is 0-1
pwp	permanent wilting point water content, range is 0-1
style	VWC classification style

Value

vector of moisture states (ordered factor)

Author(s)

D.E. Beaudette

Examples

# "very moist"
estimateSoilMoistureState(VWC = 0.3, U = 0, sat = 0.35, fc = 0.25, pwp = 0.15)
estimateSoilMoistureState(VWC = 0.3, U = 2, sat = 0.35, fc = 0.25, pwp = 0.15)

"wet"
estimateSoilMoistureState(VWC = 0.3, U = 5, sat = 0.35, fc = 0.25, pwp = 0.15)

# "very dry"
estimateSoilMoistureState(VWC = 0.15, U = 0, sat = 0.35, fc = 0.25, pwp = 0.15)

# "dry" 
estimateSoilMoistureState(VWC = 0.18, U = 0, sat = 0.35, fc = 0.25, pwp = 0.15)

sharpshootR documentation built on Nov. 5, 2025, 7:06 p.m.