Calculate the landscape-level sum of metrics for a set of landscape rasters
Details
This function will combine the landscape-specific estimates of the
total area of each land cover class provided by areadat (optionally also
by zone; see sum_landcover()) with per-unit-area metrics associated with
each land cover class as provided in metricdat. The two data sets are
joined by any fields in common, which should at minimum include a field
containing the land cover classes.
For most metrics, scores are calculated by multiplying the total area by the corresponding per-unit-area metric and summing over the entire landscape. However, for Annual Wages associated with agricultural jobs, a weighted average is instead produced, based on the average wage for an agricultural job associated with each land cover class and the proportion of the landscape that has an associated wage (i.e., only crop classes) that is made up by that land cover class. In addition, for the metrics representing the Climate Change Resilience category, the overall landscape average score is produced.
This function expects metricdat to contain the following fields:
class: a character field containing the land cover classes; may be called anything, but should match with a corresponding field in
areadatMETRIC: character field used to define specific metrics; expects a METRIC called "Annual Wages"
SCORE_MEAN, SCORE_SE: numeric fields containing the specific values for each METRIC and an estimate of uncertainty
METRIC_CATEGORY, UNIT: optional additional character fields useful for grouping METRICS and tracking units; may contain anything, will be retained in output. If UNIT is present, "/ha" will be removed from the results before returning, as a reminder that the resulting total scores are no longer per-hectare.
This function also expects areadat to contain the following fields:
scenario: character field used to identify the name of the landscape being examined
class: as above, a character field containing the land cover classes; may be called anything, but should match with a corresponding field in
metricdatarea: numeric field containing the total area of each land cover class. Take care that the units in which the area field was calculated correspond to the UNITs by which the per-unit-area METRICS in
metricdatwere defined (often ha). (Seesum_landcover().)ZONE: optional character field identifying the name of a zone within which the area of land covers was estimated, such as by running
sum_landcover()withzonesprovided; if ZONE is present, the output will be summarized by zone.