Prints table of change metrics for a given streamflow statistic

Part of the flowHistory system. Provides a measure of change (in real units and as percent per year) based on the smoothed values for various streamflow statistics. Smoothing algorithm is the same as is used in plotFlowSingle.

Usage

tableFlowChange(eList, istat, qUnit = 1, runoff = FALSE, yearPoints = NA)

Arguments

eList: named list with at least Daily and INFO dataframes
istat: A numeric value for the flow statistic to be graphed (possible values are 1 through 8)
qUnit: object of qUnit class printqUnitCheatSheet, or numeric represented the short code, or character representing the descriptive name.
runoff: logical variable, if TRUE the streamflow data are converted to runoff values in mm/day
yearPoints: A vector of numeric values, specifying the years at which change metrics are to be calculated, default is NA (which allows the function to set these automatically), yearPoints must be in ascending order

Details

The index of the flow statistics is istat. These statistics are: (1) 1-day minimum, (2) 7-day minimum, (3) 30-day minimum, (4) median (5) mean, (6) 30-day maximum, (7) 7-day maximum, and (8) 1-day maximum.

Can also run the statistics on any Period of Analysis (individual months or sequence of months) using setPA.

A dataframe is returned, as well as a printout in the R console.

Examples

eList <- Choptank_eList
tableFlowChange(eList, istat = 5, yearPoints = c(1981, 1995, 2010))
#> 
#>    Choptank River
#>    Water Year
#>     mean daily 
#> 
#>              Streamflow Trends
#>    time span          change        slope       change        slope
#>                         cfs         cfs/yr        %            %/yr
#>  1981  to  1995           21          1.5           19          1.4
#>  1981  to  2010           49          1.7           45          1.6
#>  1995  to  2010           28          1.9           22          1.4
eList <- setPA(eList, paStart = 4, paLong = 12)
tableFlowChange(eList, istat = 2, qUnit = 2, yearPoints = c(1981, 1995, 2010))
#> 
#>    Choptank River
#>    Year Starting With April
#>     7-day minimum 
#> 
#>              Streamflow Trends
#>    time span          change        slope       change        slope
#>                         cms         cms/yr        %            %/yr
#>  1981  to  1995       ---       ---       ---       ---
#>  1981  to  2010       ---       ---       ---       ---
#>  1995  to  2010       -0.036      -0.0024          -11        -0.72
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
eList <- setPA(eList, paStart = 9, paLong = 1)
df <- tableFlowChange(eList, istat = 5, qUnit = 2, yearPoints = c(1981, 1995, 2010))
#> 
#>    Choptank River
#>    Season Consisting of Sep
#>     mean daily 
#> 
#>              Streamflow Trends
#>    time span          change        slope       change        slope
#>                         cms         cms/yr        %            %/yr
#>  1981  to  1995         0.33        0.024           46          3.3
#>  1981  to  2010          0.8        0.028          110          3.8
#>  1995  to  2010         0.47        0.031           45            3
df 
#>   year1 year2 change[cms] slope[cms/yr] change[%] slope[%/yr]
#> 1  1981  1995        0.33         0.024        46         3.3
#> 2  1981  2010        0.80         0.028       110         3.8
#> 3  1995  2010        0.47         0.031        45         3.0