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Convert data to SNIRH file format

Source: R/convert_to_snirh.R
convert_to_snirh.Rd

Cleans and converts laboratory data to the SNIRH (National Information System on Water Resources) import format. It handles data validation, unit conversions, station validation, and formatting according to SNIRH standards.

Usage

convert_to_snirh(data, matrix, validate_stations = TRUE)

Arguments

data

A data.frame or data.table containing the original laboratory data. Must contain the following columns in order: snirh_entity, station_name, station_id, sampling_date, parameter, unit, value.

matrix

Character string specifying the type of matrix being processed. Must be one of: "surface.water" or "biota".

validate_stations

Logical. Whether to validate station IDs against the SNIRH database. Defaults to TRUE. Set to FALSE for offline use, testing, or matrices that don't support validation.

Value

A data.table formatted for SNIRH import with the following structure:

  • First row contains network specification (REDE=NETWORK_NAME)

  • Station identifiers (ESTACAO=STATION_ID) before each group of measurements

  • Date/time stamps in DD/MM/YYYY HH:MM format

  • Parameter values in SNIRH-compatible units and symbols

Details

The function performs several key operations:

  • Validates input data structure and removes empty rows/columns

  • Validates station IDs against SNIRH database (for surface.water and biota)

  • Checks for duplicate measurements (same station, date, and parameter)

  • Extracts pH temperature measurements when present

  • Converts measurement values to SNIRH-compatible units

  • Handles measurement flags (<, >, =) and special values

  • Formats output according to SNIRH import specifications

Station Validation

For surface.water and biota matrices, the function validates that:

  • All station IDs exist in the SNIRH database

  • All stations have status "ATIVA" (active)

  • Internet connection is available for downloading station data

If validation fails, the function will stop and provide details about invalid stations that need to be corrected in the database.

Input Data Requirements

The input data must be a data.frame/data.table with exactly these columns:

snirh_entity

Entity responsible for the data

station_name

Human-readable station name

station_id

Unique station identifier (must match SNIRH database)

sampling_date

Date and time of sampling (POSIXct recommended)

parameter

Parameter name as used in laboratory

unit

Unit of measurement as used in laboratory

value

Measured value (may include flags like <, >)

Parameter Conversion

Relies on an internal parameters dataset that maps laboratory parameter names and units to SNIRH equivalents. This dataset must contain conversion factors and SNIRH symbols for all parameters in the input data.

Examples

# Example data structure
# \donttest{
lab_data <- data.table::data.table(
  snirh_entity = "APA",
  station_name = "River station 1",
  station_id = "01F/01",  # Must be valid SNIRH station ID
  sampling_date = as.POSIXct("2024-01-15 10:30:00"),
  parameter = "pH - Campo",
  unit = "Escala Sorensen",
  value = "7.2"
)

# Convert surface water data (with station validation)
snirh_data <- convert_to_snirh(lab_data, "surface.water")

# Skip station validation if needed (not recommended)
snirh_data <- convert_to_snirh(lab_data, "surface.water",
                               validate_stations = FALSE)
# }