search

jasonelaw / nrsa

R package for calculating habitat metrics from the National Rivers and Streams Assessment protocol
3 stars 1 forks source link

General substration question - reach vs. thalweg #16

Open juliaabond opened 5 years ago

juliaabond commented 5 years ago

When looking at the NRSA codes Chris shared, I noticed that some of the metric codes have two different labels. That is, the same code is used for two separate metrics. For example, the code for percent fines for the reach is the same for the thalweg (see image below and attached spreadsheet).

image

As I have been working through the substrate metrics, I wanted to confirm that all of the pct_ values are calculated for the reach, not the thalweg. I assumed that they were all reach calculations until I noticed that the DB includes the pct_gr metric, which, from what I can tell, is only calculated for the thalweg.

Spreadsheet with codes: NRSAMetricsDescriptions.xlsx

jasonelaw commented 5 years ago

The data for these metrics is collected differently and the code is somewhat different for wadeble and non-wadeable sites. The duplicates are the wadeable vs non-wadeable metrics. I think this is something that can be pointed out in the description and that the duplicates are unnecessary and confusing from a data analysis perspective. There are differences in some wadeable sites in how the data is collected, but we don't highlight that in each metric.

jasonelaw commented 5 years ago

I should say that the source of this duplicate metric description stuff is EPA. They had different descriptions for all wadeable and non-wadeable metrics even when the metrics where calculated from identical protocols.