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Ed Lewis edited this page Oct 11, 2019 · 21 revisions

XXXX ( insert Name): an set of analytical tools for the World Database of Protected Areas

This document is to guide you through the usage of XXXX, a set of analytical tools developed to create geospatial products and statistics on the World Database of Protected Areas.

Author: Ed Lewis Supervisor: Yichuan Shi

Index

(Insert Index)

Background

The WDPA team have been running analyses on the WDPA for years. Until 2014 this were infrequent, entirely manual and extremely resource intensive. Between 2014 and 2019 the analyses were automated using Esri Modelbuilder, evolving to be run in ArcGIS Pro and at a monthly interval. From 2019 it was decided to transition away from Modelbuilder into a purely python environment. There were three major reasons for this: 1) the workflow needed to be automated to a degree beyond Modelbuilder's capabilties, 2) the model was so big that it was becoming sluggish to edit in Pro and 3) the workflow and model itself needed be more publicly available, documented and editable online. It is hoped that from early 2020 all monthly analytical components of the WDPA are run via python scripts, stored in this public, centralised and regularly updated repo.

Installation requirements

This script does not need to be run in ArcGIS software but will be run in ArcGIS Pro by UNEP-WCMC staff.

A description of the tool's inputs

This tool has (n) inputs:

  1. WDPA Public point
  2. WDPA Restricted point (CHN)
  3. WDPA Public polygon
  4. WDPA Restricted polygon (CHN)
  5. WDPA Restricted polygon (CDDA)
  6. WDPA Restricted polygon (SHN)
  7. PAME sites
  8. Baselayer (WVS-EEZ....)
  9. Baselayer tabular (WVS-EEZ...dbf format)
  10. ...

How XXXX works

**Please Note that this description covers how the model works at a high level. To know which specific tools are used, and the specific parameters of those tools then please review the script itself.

Fundamentally, the tool can be divided into 7 major steps:

  1. Preparing the WDPA for analysis;
  2. Geoprocessing the entire WDPA;
  3. Geoprocessing the entire WDPA on a country by country basis;
  4. Geoprocessing sites in the WDPA with a PAME assessment;
  5. Creating summary statistics on the entire WDPA;
  6. Creating summary statistics on the entire WDPA on a country by country basis;
  7. Creating summary statistics on sites in the WDPA with a PAME assessment.

There is currently duplication amongst these tasks, but as described below, there is a reason for this.

Step 1: Prepare the WDPA

In all WDPA analyses we remove certain sites. These are sites with a STATUS of 'Proposed' or 'Not Reported', sites with DESIG_ENG of 'UNESCO Man and Biosphere Reserve' and points without a REP_AREA value above 0. For STATUS sites, the reason is evidently that they are do not certainly protect the areas they cover. UNESCO MAB sites are removed as they have a three-tiered nesting structure, only the innermost of which is considered 'protected'. The sites in the WDPA do not yet specify which tier they are. Points with no REP_AREA are automatically removed in the buffering process.

The model begins by merging all the WDPA polygon inputs together and the WDPA point inputs together. These two merged files are then geometrically repaired. The repaired feature classes (fc) are then filtered to remove the sites listed above. The filtered points are then geodesically buffered in accordance to their REP_AREA values. The buffered points are then merged to the filtered polygons to create one definitive protected area fc 'PolyBuffpnt'.

Step 2: Geoprocessing the entire WDPA

This is one of the biggest steps.

The PolyBuffpnt undergoes a Union with itself, splitting up the WDPA into all overlapping component parts. (Insert image?) The XY centroid of each polygon is calculated. Those polygons with overlapping XY centroids are removed, dissolved flat to remove their overlaps and then put back. The now flat WDPA layer is now intersected with the baselayer The intersected flat WDPA layer is projected into the equal area projection Mollweide The projected layer has the area of each polygon calculated

Step 3: Geoprocessing the entire WDPA by country

Q: Why do we geoprocess again by country? **A: When we geoprocess the entire WDPA (step 1) we disregard what country submitted what site. When we report country stats we do not define a country's network based on geographic delineations (i.e. country boundaries), instead we report based on all sites that have that country's ISO3166 code. The major reason for this is PA boundaries can often be of variable accuracy and rarely align to country boundaries (which can also be disputed), thus you can easily artificially insert false negatives/positives into country reporting this way (it's also prone to political disagreement).

This branch of the model starts with the PolyBuffpnt and has a very similar set of tools as Step 2.

Sites with a single ISO3 code (i.e. 'BRA') are selected from PolyBuffpnt into a separate fc Site with multiple ISO3 codes (i.e. 'BRA;ECU') are selected from PolyBuffpnt into a separate fc

Step 4:

Step 5:

Step 6:

Step 7:

Step 8:

Step 2:

Installing and using XXXX in ArcGIS Pro

Troubleshooting common errors

Q: Why do UNEP-WCMC country stats differ from official nationally reported stats? **A:

Q: Why don't we use geographic delineation for ABNJ coverage? **A:

Q: Why do we remove Antarctica from the terrestrial global coverage statistics? **A:

Exploring the outputs

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