Dataset: Possible Tree Canopy - Vegetation %

About this Dataset

Possible Tree Canopy - Vegetation %

This data layer references data from a high-resolution tree canopy change-detection layer for Seattle, Washington. Tree canopy change was mapped by using remotely sensed data from two time periods (2016 and 2021). Tree canopy was assigned to three classes: 1) no change, 2) gain, and 3) loss. No change represents tree canopy that remained the same from one time period to the next. Gain represents tree canopy that increased or was newly added, from one time period to the next. Loss represents the tree canopy that was removed from one time period to the next. Mapping was carried out using an approach that integrated automated feature extraction with manual edits. Care was taken to ensure that changes to the tree canopy were due to actual change in the land cover as opposed to differences in the remotely sensed data stemming from lighting conditions or image parallax. Direct comparison was possible because land-cover maps from both time periods were created using object-based image analysis (OBIA) and included similar source datasets (LiDAR-derived surface models, multispectral imagery, and thematic GIS inputs). OBIA systems work by grouping pixels into meaningful objects based on their spectral and spatial properties, while taking into account boundaries imposed by existing vector datasets. Within the OBIA environment a rule-based expert system was designed to effectively mimic the process of manual image analysis by incorporating the elements of image interpretation (color/tone, texture, pattern, location, size, and shape) into the classification process. A series of morphological procedures were employed to ensure that the end product is both accurate and cartographically pleasing. No accuracy assessment was conducted, but the dataset was subjected to manual review and correction.

University of Vermont Spatial Analysis Laboratory in collaboration with City of Seattle.

This dataset consists of City of Seattle SDOT Urban Forestry Management Units which cover the following tree canopy categories:

Existing tree canopy percent
Possible tree canopy - vegetation percent
Relative percent change
Absolute percent change

For more information, please see the 2021 Tree Canopy Assessment.
Organization: City of Seattle
Last updated: 2025-02-28T23:21:02.555686
Tags: 2016, 2021, biota, environment, land-cover, seattle, seattle-gis-open-data, seattle-office-of-sustainability-environment, tree-canopy

Tables

Table 1

@usgov.city_of_seattle_possible_tree_canopy_vegetation_fbb60.table_1

41.45 KB
27 rows
50 columns


CREATE TABLE table_1 (
  "objectid_12_13" BIGINT,
  "management_units" BIGINT,
  "tc_id" BIGINT,
  "objectid" BIGINT,
  "tc_id_1" VARCHAR,
  "total_a" BIGINT,
  "can_a" BIGINT,
  "grass_a" BIGINT,
  "soil_a" BIGINT,
  "water_a" BIGINT,
  "build_a" BIGINT,
  "road_a" BIGINT,
  "paved_a" BIGINT,
  "perv_a" BIGINT,
  "imperv_a" BIGINT,
  "can_p" DOUBLE,
  "grass_p" DOUBLE,
  "soil_p" DOUBLE,
  "water_p" DOUBLE,
  "build_p" DOUBLE,
  "road_p" DOUBLE,
  "paved_p" DOUBLE,
  "perv_p" DOUBLE,
  "imperv_p" DOUBLE,
  "objectid_1" VARCHAR,
  "tc_e_a" BIGINT,
  "tc_pv_a" BIGINT,
  "tc_land_a" BIGINT,
  "tc_pi_a" BIGINT,
  "tc_p_a" BIGINT,
  "tc_e_p" DOUBLE,
  "tc_pv_p" DOUBLE,
  "tc_p_p" DOUBLE,
  "tc_pi_p" DOUBLE,
  "tc_land_a_1" VARCHAR,
  "gain" BIGINT,
  "loss" BIGINT,
  "no_change" BIGINT,
  "treecanopy_2016_area" BIGINT,
  "treecanopy_2021_area" BIGINT,
  "change_area" BIGINT,
  "change_percentchange" DOUBLE,
  "treecanopy_2016_percent" DOUBLE,
  "treecanopy_2021_percent" DOUBLE,
  "change_percent_absdiff" DOUBLE,
  "tc_id_12" VARCHAR,
  "objectid_12" VARCHAR,
  "tc_id_12_13" VARCHAR,
  "shape_area" DOUBLE,
  "shape_length" DOUBLE
);