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Read TERN SMIPS Soil Moisture Data

Source: R/read_smips.R
read_smips.Rd

Wrapper around read_tern() for TERN/SMIPS daily soil moisture data. Provides soil moisture estimates at 1 km resolution from November 2015 to approximately 7 days before today.

Usage

read_smips(
  date,
  collection = "totalbucket",
  api_key = NULL,
  max_tries = 3L,
  initial_delay = 1L
)

Arguments

date

A day to download (Date or character, e.g. "2024-01-15" or as.Date("2024-01-15")). Required.

collection

SMIPS collection variant (default "totalbucket"). Options:

"totalbucket"

Total soil moisture in the full active layer (mm). Represents the total water stored in all soil layers of the active profile. Use for: Overall soil water availability, drought monitoring. Output column: SMIPS_totalbucket

"SMindex"

Soil Moisture Index, 0-100% (standardized metric). Rescaled to 0-100% for comparison across regions and seasons. Use for: Regional comparisons, anomaly detection, percentage-based thresholds. Output column: SMIPS_SMindex

"bucket1"

Top soil layer moisture (mm, typically 0-10 cm). Represents water in surface soil where seeds germinate and shallow roots operate. Use for: Shallow-rooting plants, seed germination, surface runoff prediction. Output column: SMIPS_bucket1

"bucket2"

Second soil layer moisture (mm, typically 10-40 cm). Represents water in intermediate soil depth where many plant roots develop. Use for: Typical crop rooting depth, plant-available water. Output column: SMIPS_bucket2

"deepD"

Deep soil layer moisture (mm, typically >40 cm). Represents water in deeper soil layers accessed by deep-rooting plants. Use for: Deep-rooting trees/shrubs, groundwater recharge, long-term drought. Output column: SMIPS_deepD

"runoff"

Surface runoff (mm). Represents water predicted to run off the surface (not infiltrate). Use for: Flood risk, erosion modeling, drainage engineering. Output column: SMIPS_runoff

api_key

A character string containing your TERN API key. Defaults to automatic detection from your .Renviron or .Rprofile. See get_key() for setup.

max_tries

An integer giving the maximum number of download retries before an error is raised. Defaults to 3.

initial_delay

An integer giving the initial retry delay in seconds (doubles with each attempt). Defaults to 1.

Value

A terra::rast() object of the requested SMIPS collection.

References

SMIPS portal: https://portal.tern.org.au/metadata/TERN/d1995ee8-53f0-4a7d-91c2-ad5e4a23e5e0

See also

read_tern(), read_aet(), read_asc()

Examples

if (FALSE) { # interactive()
# Total bucket soil moisture (default)
r <- read_smips("2024-01-15")
autoplot(r)

# Soil moisture index (0-100%)
r_smi <- read_smips("2024-01-15", collection = "SMindex")

# Top soil bucket (shallow rooting plants)
r_bucket1 <- read_smips("2024-01-15", collection = "bucket1")

# Deep soil layer (deep rooting plants)
r_deep <- read_smips("2024-01-15", collection = "deepD")

# Surface runoff
r_runoff <- read_smips("2024-01-15", collection = "runoff")
}