README.md

COMBINE

Description

The WENR Combine tool combines two or more categorical geospatial rasters. It creates a new geospatial integer raster in which each value points to a unique combination of categories of the input rasters. The key to the unique combinations is provided in a *.csv table.

This is an open source adaptation of the ArcGIS Pro Combine Tool.

The illustration below demonstrates the Combine tool.

Left and center are two integer arrays, called 'beheertypen' and 'top10'. These are the two input rasters. The Combine tool output is shown on the right. It is an array of euqal dimensions. The values in it point to specific combinations of 'beheertypen' and 'top10'. The associated table would look like:

value	beheertypen	top10
1	10	160
2	10	100
3	10	143
4	11	142
5	11	143
6	11	144
7	11	100
8	12	161
9	13	144

The combine tool is designed for use in conjunction with the Multi-Reclass Tool.

Installation

The Combine tool requires a Python environment with the following modules installed:

• numpy
• pandas
• rasterio
• prefect 1.0

Usage

Use the Command Line Interface to handle the Combine tool. Positional arguments are:

positional arguments:
  destination  path to destination *.tif file
  sources      path to destination source files

options:
  -h, --help   show this help message and exit
  --test       test run with 20 windows

For example, the following input takes 2 input rasters:

python COMBINE.py c:/apps/test_combine/combinations01.tif c:/apps/test_data/top10.tif c:/apps/test_data/beheertypen.tif

The output would be:

c:\apps\test_combine\combinations01.tif <<-- the Geospatial raster
c:\apps\test_combine\combinations01.csv <<-- CSV file with key to the output TIFF

For testing purposes, add --test to the Command Line command. This restricts the tool to only 20 sub-windows.

Users within the WUR network can use the following commands for testing purposes.

Testing run: python COMBINE.py <output_location>.tif w:\PROJECTS\DUIN\Data\NATUUR\BasisbestandNatuurLandschap\BNL2020\Bedrijventerrein_Pos5_20210315time162111.tif w:\PROJECTS\DUIN\Data\NATUUR\BasisbestandNatuurLandschap\BNL2020\OAD_Bebkom_Top10_Vlak_2020_sept_Pos4_20210302time141928.tif w:\PROJECTS\DUIN\Data\NATUUR\BasisbestandNatuurLandschap\BNL2020\Top10_Vlak_2020_sept_Pos1_20210325time161731.tif --test

Full run: python COMBINE.py <output_location>.tif w:\PROJECTS\DUIN\Data\NATUUR\BasisbestandNatuurLandschap\BNL2020\Bedrijventerrein_Pos5_20210315time162111.tif w:\PROJECTS\DUIN\Data\NATUUR\BasisbestandNatuurLandschap\BNL2020\OAD_Bebkom_Top10_Vlak_2020_sept_Pos4_20210302time141928.tif w:\PROJECTS\DUIN\Data\NATUUR\BasisbestandNatuurLandschap\BNL2020\Top10_Vlak_2020_sept_Pos1_20210325time161731.tif

Details

The Combine tool verifies that all input rasters have an identical extent and resolution, and quits if this is not the case.

The Combine tool subdivides the geographical extent of the input rasters into many windows, which are processed in parallel. The default window size is 2.000 X 2.000 pixels. The tool assumes that the input raster width and height are conmensurable with the window size. This is assumed but not verified.

The Combine tool writes temporary files to disk. Around ~60GB local storage capacity is required.

Run time for combining 7 rasters with shape 112.000 X 130.000 on a 16GB RAM laptop is 5.5 hours.

Support

Get in touch with Hans.

Authors and acknowledgment

Thanks to Johan B: https://stackoverflow.com/a/59962140/981768

License

CC BY-NC-SA 4.0