GCAM boundary spatial products from moirai v3.1

Summary- These data products present vector files for different representations of land area from the moirai land data system. Vector files are generated at 3 main spatial levels, namely country, region, basin. In addition to this, files are generated for different intersections for the 3 main categories, intersections for country and basin boundaries (country_basin), region and basin boundaries (region_basin) and region and country boundaries (region_country). Since the land data system does not generate land area information for all cells within the above mentioned boundaries (for water bodies for example), the vectors are presented for 3 main classes for each spatial category, land cells, cells with no land and combined. With all of the above mentioned combinations, the data products contain 18 different vector files.

Methodology- In generating these vector files, we used the land outputs from moirai as inputs along with separate inputs for the boundaries for the main spatial levels (country, basin and region). Combining the spatial boundaries with land inputs we generated 3 raster outputs (land, no land and combined) for each of the main spatial levels along with all the intersections. A unique key is assigned for each unique spatial boundary.  We then converted these rasters to vectors through a process of polygonization where polygons were dissolved using the key and finally added all metadata (basin names, region names, country names) to each of the vector files. We check and correct geometry errors in the polygons themselves. We also added various validation tests to the code to account for completeness and accuracy.

CONTENTS:

gcam_boundaries_moirai_3p1_0p5arcmin_wgs84 folder contains the following,

  spatial_input_files contain the following,

• valid_land_area.bil: raster file containing actual land area by grid cell globally.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• country_out.bil: raster file containing valid land cells matched to country codes.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• country_out_noland.bil: raster file containing non-land cells matched to country codes.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• glu_raster.bil: raster file containing valid land cells matched to GLU codes.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• glu_raster_noland.bil: raster file containing non-land cells matched to GLU codes.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• region_gcam_out.bil: raster file containing valid land cells matched to GCAM region codes.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• region_gcam_out_noland.bil: raster file containing non-land cells matched to GCAM region codes.

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins (Generated by the moirai LDS)

• Global235_CLM_5arcmin.bil: raster file containing basin boundaries for all cells output by moirai

crs: EPSG:4326 WGS84 - World Geodetic System 1984

resolution: 0.5 arc mins

• GCAM_region_names.csv- Mapping file with details on GCAM region names (Used to fill in metadata)
• iso_GCAM_regID.csv- Mapping file containing details on individual country names by iso code. (Used to fill in metadata)
• basin_to_country_mapping.csv – Mapping file containing details on basin names by country and region. (Used to fill in metadata),

main_outputs contains the following,

      column names in outputs:

• key: Unique identifier for feature
• reg_id: Unique identifier for region (region number)
• ctry_id: Unique identifier for country (country number)
• glu_id: Unique identifier for basin (basin number)
• reg_nm: Region name
• ctry_nm: Country name
• glu_nm: Basin name

See the README for more details on the data