`R/screen_flow_data.R`

`screen_flow_data.Rd`

Calculates means, medians, maximums, minimums, standard deviations of annual flows and data availability and missing data statistics for each year and month of each year. Calculates the statistics from all daily discharge values from all years, unless specified. Returns a tibble with statistics.

screen_flow_data( data, dates = Date, values = Value, groups = STATION_NUMBER, station_number, roll_days = 1, roll_align = "right", water_year_start = 1, start_year, end_year, months = 1:12, transpose = FALSE )

data | Data frame of daily data that contains columns of dates, flow values, and (optional) groups (e.g. station numbers).
Leave blank if using |
---|---|

dates | Name of column in |

values | Name of column in |

groups | Name of column in |

station_number | Character string vector of seven digit Water Survey of Canada station numbers (e.g. |

roll_days | Numeric value of the number of days to apply a rolling mean. Default |

roll_align | Character string identifying the direction of the rolling mean from the specified date, either by the first
( |

water_year_start | Numeric value indicating the month ( |

start_year | Numeric value of the first year to consider for analysis. Leave blank to use the first year of the source data. |

end_year | Numeric value of the last year to consider for analysis. Leave blank to use the last year of the source data. |

months | Numeric vector of months to include in analysis (e.g. |

transpose | Logical value indicating whether to transpose rows and columns of results. Default |

A tibble data frame with the following columns:

calendar or water year selected

number of days per year

number of days per year with flow data

number of days per year with no flow data

annual minimum of all daily flows for a given year

annual maximum of all daily flows for a given year

annual mean of all daily flows for a given year

annual median of all daily flows for a given year

annual 1 standard deviation of all daily flows for a given year

number of Jan days per year with no flow data

number of Feb days per year with no flow data

number of Mar days per year with no flow data

number of Apr days per year with no flow data

number of May days per year with no flow data

number of Jun days per year with no flow data

number of Jul days per year with no flow data

number of Aug days per year with no flow data

number of Sep days per year with no flow data

number of Oct days per year with no flow data

number of Nov days per year with no flow data

number of Dec days per year with no flow data

# Run if HYDAT database has been downloaded (using tidyhydat::download_hydat()) if (file.exists(tidyhydat::hy_downloaded_db())) { # Calculate screening statistics usinga data frame and data argument with defaults flow_data <- tidyhydat::hy_daily_flows(station_number = "08NM116") screen_flow_data(data = flow_data) # Calculate screening statistics using station_number argument with defaults screen_flow_data(station_number = "08NM116") # Calculate screening statistics for water years starting in October screen_flow_data(station_number = "08NM116", water_year_start = 9) # Calculate screening statistics for 7-day flows for July-September months only screen_flow_data(station_number = "08NM116", roll_days = 7, months = 7:9) }#> # A tibble: 69 x 13 #> STATION_NUMBER Year n_days n_Q n_missing_Q Minimum Maximum Mean Median #> <chr> <dbl> <int> <int> <int> <dbl> <dbl> <dbl> <dbl> #> 1 08NM116 1949 92 92 0 0.838 4.29 1.52 1.32 #> 2 08NM116 1950 92 92 0 0.714 16.6 2.71 1.36 #> 3 08NM116 1951 92 92 0 0.629 8.80 2.21 1.23 #> 4 08NM116 1952 92 92 0 1.11 12.9 2.85 1.93 #> 5 08NM116 1953 92 92 0 0.821 24.1 4.77 2.24 #> 6 08NM116 1954 92 92 0 1.98 30.5 7.65 4.34 #> 7 08NM116 1955 92 92 0 0.396 19.9 4.82 2.35 #> 8 08NM116 1956 92 92 0 0.784 8.21 2.25 1.29 #> 9 08NM116 1957 92 92 0 0.916 6.23 2.36 1.92 #> 10 08NM116 1958 92 92 0 0.578 5.51 1.71 1.23 #> # ... with 59 more rows, and 4 more variables: StandardDeviation <dbl>, #> # Jul_missing_Q <int>, Aug_missing_Q <int>, Sep_missing_Q <int>