A dataset containing data on tree canopy coverage and change for the city of Boston, Massachusetts from 2014-2019, as well as temperature and heat index data for July 2019. Data is aggregated to a grid of regular 25 hectare hexagons, clipped to city boundaries. This data is made available under the Public Domain Dedication and License v1.0 whose full text can be found at: https://opendatacommons.org/licenses/pddl/1-0/.

## Format

A data frame (of class `sf`

, `tbl_df`

, `tbl`

, and `data.frame`

)
containing 682 records of 22 variables:

- grid_id
Unique identifier for each hexagon. Letters represent the hexagon's X position in the grid (ordered West to East), while numbers represent the Y position (ordered North to South).

- land_area
Area excluding water bodies

- canopy_gain
Area of canopy gain between the two years

- canopy_loss
Area of canopy loss between the two years

- canopy_no_change
Area of no canopy change between the two years

- canopy_area_2014
2014 total canopy area (baseline)

- canopy_area_2019
2019 total canopy area

- change_canopy_area
The change in area of tree canopy between the two years

- change_canopy_percentage
Relative change calculation used in economics is the gain or loss of tree canopy relative to the earlier time period: (2019 Canopy-2014 Canopy)/(2014 Canopy)

- canopy_percentage_2014
2014 canopy percentage

- canopy_percentage_2019
2019 canopy percentage

- change_canopy_absolute
Absolute change. Magnitude of change in percent tree canopy from 2014 to 2019 (% 2019 Canopy - % 2014 Canopy)

- mean_temp_morning
Mean temperature for July 2019 from 6am - 7am

- mean_temp_evening
Mean temperature for July 2019 from 7pm - 8pm

- mean_temp
Mean temperature for July 2019 from 6am - 7am, 3pm - 4pm, and 7pm - 8pm (combined)

- mean_heat_index_morning
Mean heat index for July 2019 from 6am - 7am

- mean_heat_index_evening
Mean heat index for July 2019 from 7pm - 8pm

- mean_heat_index
Mean heat index for July 2019 from 6am - 7am, 3pm - 4pm, and 7pm - 8pm (combined)

- geometry
Geometry of each hexagon, encoded using EPSG:2249 as a coordinate reference system (NAD83 / Massachusetts Mainland (ftUS)). Note that the linear units of this CRS are in US feet.

## Source

Canopy data is from https://data.boston.gov/dataset/hex-tree-canopy-change-metrics2. Heat data is from https://data.boston.gov/dataset/hex-mean-heat-index2. Most field definitions are from https://data.boston.gov/dataset/canopy-change-assessment-data-dictionary.

## Details

Note that this dataset is in the EPSG:2249
(NAD83 / Massachusetts Mainland (ftUS)) coordinate reference system (CRS),
which may not be installed by default on your computer. Before working with
`boston_canopy`

, run:

`sf::sf_proj_network(TRUE)`

to install the CRS itself`sf::sf_add_proj_units()`

to add US customary units to your units database

These steps only need to be taken once per computer (or per PROJ installation).