title: “USACE 3 factor vs NWI wetlands” subtitle: “Vector analysis – combining new and AAv11” author: “E Gage” date: “2016-12-02” output: tint::tintHtml: self_contained: TRUE bibliography: skeleton.bib link-citations: yes —

Objectives

1. Compare the number and area of wetlands mapped by 3-factor and NWI wetlands across study sites

2. Evaluate correlates of differences in mapping outcomes

Quantifying differences between maps

Total area mapped:

Perhaps the most straigfoward calculation. The simple sum of all wetland polygons for a given mapping protocol.

The formulation for 3-factor wetlands: \[{A_{3f}} = 100*\sum_{i=1}^{n}A_{i}\]

The formulation for NWI wetlands: \[{A_{NWI}} = 100*\sum_{i=1}^{n}A_{i}\]

Total polygons mapped:

The count of all wetland polygons for a given mapping protocol.

The formulation for 3-factor wetlands: \[{n_{3f poly}} = 100*\sum_{i=1}^{n}n_{i}\]

The formulation for NWI wetlands: \[{A_{NWI poly}} = 100*\sum_{i=1}^{n}n_{i}\]

Normalized Difference Area Index:

\[NDAI = \frac{({A_{3f}} - {A_{NWI}})}{({A_{3f}} + A_{NWI})}\]

Sumarize the total area and number of AA (v11)

Here’s where I read in and export AA v11 centroids as shapefile

## OGR data source with driver: ESRI Shapefile 
## Source: "data/Final_shapefile", layer: "AA_v11_centroids"
## with 769 features
## It has 13 fields

## OGR data source with driver: ESRI Shapefile 
## Source: "data/Final_shapefile", layer: "AAv11centr_DivDist_Join"
## with 769 features
## It has 21 fields

summarized AA area and count by USACE Division

## Joining, by = "DIVISION"

summarized AA area and count by USACE District

AA omernick

** plot of AA area by omerL3 **

UNION analysis

## OGR data source with driver: ESRI Shapefile 
## Source: "data/Final_shapefile", layer: "UnionFin_3fNWI_fAAv12_v2"
## with 92382 features
## It has 41 fields

Summarize area across all sites

Omernik Ecoregions