In ebimodeling/ghgvcR: Greenhouse Gas Value Calculator

The Greenhouse Gas Value Calculator (GHGVC) uses the ghgvcR package to calculate greenhouse gas emissions. GHGVC can be installed at https://github.com/ebimodeling/ghgvc.

Citation: Kristina J. Teixeira and Evan H. Delucia 2011. The greenhouse gas value of ecosystems. Global Change Biology. 17(1):425438 doi: 10.1111/j.1365-2486.2010.02220.x

Overview

ghgvcR has two principal functions:

1. get_ncdf() reads in netcdf biome data.
2. ghgvcr() calculates the greenhouse gas emissions of a specific ecosystem.

These functions are implemented in two scripts in the inst/scripts directory of the ghgvcR package: get_biome.R and calc_ghgv.R. get_biome.R is used by GHGVC to load biome data from netcdf4 files. calc_ghgv.R is used by GHGVC to calculate greenhouse gas emissions and write the results to a json file.

Quick Example

Several example ecosystem data files are kept in inst/config_examples/. These can be used in place of biome data to run the calculator entirely within R:

library(ghgvcr)

#load example config data
config_file <- system.file("config_examples/multisite_config.xml", package = "ghgvcr")
config <- XML::xmlToList(XML::xmlParse(config_file))  

#Calculate 
res <- ghgvc(config)

#Write the data to a file:
#outdir <- "./"
#write_json(res, outdir, filename = "ghgvc_example", format="json")

ghgvcR can also plot the greenhouse gas values that are returned by ghgvc():

``` {r, fig.show='hold'} df <- as.data.frame(res$site_1_data)

p <- ghgvc_plot(df, save = FALSE)

p

####Biome Example 
The same calculation can be done for a specific location if biome data is available.

```r
#NOT RUN 
library(ghgvcr)

#Example location
latitude <- 40.18
longitude <- -89.82

#paths
netcdf_dir <- "<data directory>"
named_ecosystems <- "<named ecosystems file>"

#Load the biome data for that location
biome <- get_biome(latitude, longitude, netcdf_dir, named_ecosystems, write_data = FALSE)
head(biome)

#Calculate GHGV
#res <- ghgvc(biome)

Working with GHGVC

ghgvcR works in concert with ghgvc through the ghgvcR scripts. This requires a certain amount of configuration. Once ghgvc is set up correctly, the following settings must be configured in app/workflows_controller.rb:

Where to find the ghgvcR scripts ghgvcR_scripts_path needs to be set. In development this is currently "/inst/scripts". In production, it may be better to place the scripts directory within the ghgvc app itself (e.g. "/ghgvcR/").

Where the netcdf data is stored By default the netcdf data is stored at "/netcdf/".

Where the name-indexed ecosystem json file is stored By default this is "/public/data/final_ecosystems.json".

ebimodeling/ghgvcR documentation built on April 28, 2021, 8:19 p.m.