Query soil/climate data from USDA-NRCS SCAN Stations

fetchSCAN(
  site.code = NULL,
  year = NULL,
  report = "SCAN",
  timeseries = c("Daily", "Hourly"),
  ...
)

SCAN_sensor_metadata(site.code)

SCAN_site_metadata(site.code = NULL)

Arguments

site.code

a vector of site codes. If NULL SCAN_site_metadata() returns metadata for all SCAN sites.

year

a vector of years

report

report name, single value only; default 'SCAN', other example options include individual sensor codes, e.g. 'SMS' for Soil Moisture Storage, 'TEMP' for temperature

timeseries

either 'Daily' or 'Hourly'

...

additional arguments. May include intervalType, format, sitenum, interval, year, month. Presence of additional arguments bypasses default batching functionality provided in the function and submits a 'raw' request to the API form.

Value

a list of data.frame objects, where each element name is a sensor type, plus a metadata table; different report types change the types of sensor data returned. SCAN_sensor_metadata() and SCAN_site_metadata() return a data.frame. NULL on bad request.

Details

Possible above and below ground sensor types include: 'SMS' (soil moisture), 'STO' (soil temperature), 'SAL' (salinity), 'TAVG' (daily average air temperature), 'TMIN' (daily minimum air temperature), 'TMAX' (daily maximum air temperature), 'PRCP' (daily precipitation), 'PREC' (daily precipitation), 'SNWD' (snow depth), 'WTEQ' (snow water equivalent),'WDIRV' (wind direction), 'WSPDV' (wind speed), 'LRADT' (solar radiation/langley total).

SCAN Sensors

All Soil Climate Analysis Network (SCAN) sensor measurements are reported hourly.

Element MeasuredSensor TypePrecision
Air TemperatureShielded thermistor0.1 degrees C
Barometric PressureSilicon capacitive pressure sensor1%
PrecipitationStorage-type gage or tipping bucketStorage: 0.1 inches;
Relative HumidityThin film capacitance-type sensor1%
Snow DepthSonic sensor (not on all stations)0.5 inches
Snow Water ContentSnow pillow device and a pressure transducer (not on all stations)0.1 inches
Soil MoistureDielectric constant measuring device. Typical measurements are at 2", 4", 8", 20", and 40" where possible.0.50%
Soil TemperatureEncapsulated thermistor. Typical measurements are at 2", 4", 8", 20", and 40" where possible.0.1 degrees C
Solar RadiationPyranometer0.01 watts per meter
Wind Speed and DirectionPropellor-type anemometerSpeed: 0.1 miles per hour; Direction: 1 degree

SNOTEL Sensors

All Snow Telemetry (SNOTEL) sensor measurements are reported daily.

Element MeasuredSensor TypePrecision
Air TemperatureShielded thermistor0.1 degrees C
Barometric PressureSilicon capacitive pressure sensor1%
PrecipitationStorage-type gage or tipping bucketStorage: 0.1 inches; Tipping bucket: 0.01 inches
Relative HumidityThin film capacitance-type sensor1%
Snow DepthSonic sensor0.5 inches
Snow Water ContentSnow pillow device and a pressure transducer0.1 inches
Soil MoistureDielectric constant measuring device. Typical measurements are at 2", 4", 8", 20", and 40" where possible.0.50%
Soil TemperatureEncapsulated thermistor. Typical measurements are at 2", 4", 8", 20", and 40" where possible.0.1 degrees C
Solar RadiationPyranometer0.01 watts per meter
Wind Speed and DirectionPropellor-type anemometerSpeed: 0.1 miles per hour; Direction: 1 degree

See the fetchSCAN tutorial for additional usage and visualization examples.

References

See the National Water and Climate Center home page for more information on the SCAN and SNOTEL programs, information on web services, and interactive maps of snow water equivalent, precipitation and streamflow.

Author

D.E. Beaudette, A.G. Brown

Examples

if (FALSE) {
    # get data
    x <- try(fetchSCAN(site.code=c(356, 2072), year=c(2015, 2016)))
    str(x)

    # get sensor metadata
    m <- SCAN_sensor_metadata(site.code=c(356, 2072))

    # get site metadata
    m <- SCAN_site_metadata(site.code=c(356, 2072))

    # get hourly data (396315 records)
    # x <- try(fetchSCAN(site.code=c(356, 2072), year=c(2015, 2016), timeseries = "Hourly"))
}