Mangroves Analysis - wri/gfw-analysis GitHub Wiki
Blue Raster Approach for Mangroves Analysis Process
Last updated: 12/02/2014
The initial mangroves dataset can be found here: http://earthenginepartners.appspot.com/science-2013-global-forest/download_v1.1.html
--Do some general data cleanup to ensure integrity
- Create GDB and import the shapefile to a feature class
- Run Multipart to Singlepart GP Tool
- Run Repair Geometry GP Tool
--Since data is being aggregated to the continent-level…
- Intersect with Continents layer (D:\GIS Data\Mangroves\Mangroves_processing.gdb) to get Regions (Africa, Asia, Asia_Insular, Australia, NorthAmerica, SouthAmerica, NewZealand, Pacific)
- Run Repair Geometry GP Tool
- Export by Region (to get 8 layers)
--Since there are roughly 1,255,288 records…
- Create Fishnet Grid (GP Tool) on extent of each of the 8 layers:
- Cell Size Width: 25000
- Cell Size Height: 25000
- Uncheck the box to “Create Label Points”
- Geometry Type to: Polygon
- Environments:
- Coordinate System: Eckert IV
- Processing Extent: Same as Polygon
--Clip the Fishnet to the original region mangroves layer (ie. Clip Australia_Fishnet to Mangroves_Australia)
--Add fields for Region and Script_ID (=objectID in field calculator)
--Run the python script (this script will run the Tabulate Area GP tool on each objectID and then append it into one table)
- Python Script
- Convert values from SqM to HA (using field calculator, divide values by 10,000)
Note: Certain objectID's will cause the script to fail because of extent issues. To save time, use a definition query to leave these objectID's out of the feature class passed through the script.
- North America: exclude IDs 114, 246, 451 & 1001
- Australia: exclude IDs 505
- Asia_Insular: exclude IDs 259, 766, 1183, 1560, 1563, 1602, 2194, 242