NOTE: This package is under development, and a few functions are undergoing a re-write. More complete documentation and test cases are in progress.

icicle

The goal of icicle is to calculate and tidy ice cycle variables from flow data collected by the Water Survey of Canada. This package provides a set of functions that calculate the freeze/thaw dates, onset of freshet, and length of continuous ice coverage for each year. Additional tidying functions remove years from the dataframe with consecutive NA values, and add a column for “day of the year”.

Installation

You can install the development version of icicle from GitHub with:

#install.packages("devtools")
devtools::install_github("Jacqui-123/icicle")

Example

This is a basic example of how you might use the functions in this package:

#import data for a water station from the Water Survey of Canada using tidyhydat::hy_daily_flows()
#here we use a test data file:
data_example <- read.csv("testdata.csv")

Date	waterYear	STATION_NUMBER	Parameter	Value	Symbol
10/1/1960	1961	07HA001	Flow	1140	NA
10/2/1960	1961	07HA001	Flow	1080	NA
10/3/1960	1961	07HA001	Flow	1030	E
10/4/1960	1961	07HA001	Flow	980	NA

Add a Julian date, or “day of the year” column to the data frame

data_doy <- icicle::ice_day_of_wyear(data_example)

Date	waterYear	STATION_NUMBER	Parameter	Value	Symbol	day_of_year
10/1/1960	1961	07HA001	Flow	1140	NA	1
10/2/1960	1961	07HA001	Flow	1080	NA	2
10/3/1960	1961	07HA001	Flow	1030	E	3
10/4/1960	1961	07HA001	Flow	980	NA	4

Calculate the length of continuous ice coverage using the “B” dates marked on the Water Survey of Canada’s database

library(icicle)
results_g1 <- ice_group_1(data_doy)

Year	Ice_coverage
1961	164
1962	176
1963	167
1964	173

Plot the length of continuous ice coverage per year to visualize change over time

Calculate the freeze and thaw dates for each year using the onset of continuous “B” dates

library(icicle)
results_g2 <- ice_group_2(data_doy)

	Year	Freeze_Date	Freeze_DOY	Flow_Freeze	Thaw_Date	Thaw_DOY	Flow_Thaw
7	1967	0011-01-19	32	1290	0005-05-19	217	4300
8	1968	0011-09-19	40	813	0002-06-19	129	323
9	1969	0011-07-19	38	697	NA	203	1970

```