inst/helpfiles/tab5_guideline.md

In poissonconsulting/shinyrems: Shiny Interface to 'rems' and 'wqbc'

Determining Water Quality Guideline

There are two options:

Set manually

Any benchmark value may be entered here. Examples include permit limits, water quality objectives, or water quality guidelines that are not calculated see Limits in the Reference Tables tab or visit the Water Quality Guideline app).

Calculate from data

Calculates the approved upper water quality thresholds for freshwater life in British Columbia (see Limits in Reference Tables tab for approved upper thresholds). Only limits whose conditions are met are returned.

Two options may be set by the user: 'term' and 'Get modelled estimate'.

Term

Term options include 'short', 'long' and 'long-daily'.

For long-term limits there must be at least 5 values spanning 21 days. As replicates are averaged prior to calculating the limits each of the 5 values must be on a separate day. The first 30 day period begin at the date of the first reading while the next 30 day period starts at the date of the first reading after the previous period and so on. The only exception to this is if the user provides dates in which case each period extends for 30 days or until a provided date is reached. It is important to note that the averaging of conditional variables, the 5 in 30 rule and the assignment of 30 day periods occurs independently for all combination of factor levels in the columns specified by by.

'Long-daily' term uses long-term limits on daily values.

Get modelled estimate

A limit may depend on another variable such as pH, Total Chloride, or Total Hardness and in some cases no value was recorded for the date of interest.

If the 'Get modelled estimate box' is unchecked:

The pH, Total Chloride or Total Hardness value is assumed to be the average recorded value over the 30 day period.

If the 'Get modelled estimate box' is checked:

A parametric model is used to predict the pH, Total Chloride and Total Hardness for all dates with a value of any variable. Existing values are replaced. If, in every year, there are less then 12 pH/Total Chloride/Total Hardness then an average value is taken. Otherwise, if there is only one year with 12 or more values a simple seasonal smoother is used. If there is two years with 12 or more values then a seasonal smoother with a trend is fitted. Otherwise a model with trend and a dynamic seasonal component is fitted.

poissonconsulting/shinyrems documentation built on Jan. 3, 2024, 8:04 p.m.