Getting Started

What is GEMMA?

GEMMA stands for GIS Extension for Map Management and Analysis. It is a QGIS processing plugin developed by the Geospatial Management Division (GMD) of the Philippine Statistics Authority (PSA).

The plugin provides a comprehensive set of GIS tools for map management and analysis activities, including boundary checking, geometry repair, metadata management, and field data collection packaging.

Requirements

Requirement	Minimum Version
QGIS	3.0 or later
Python	3.x (bundled with QGIS)
OS	Windows, macOS, or Linux

Installation

Method 1: QGIS Plugin Repository (Recommended)

Installing via custom repository allows QGIS to automatically detect and notify you of plugin updates:

1. Open QGIS.

2. Go to Plugins → Manage and Install Plugins.

3. Select the Settings tab.

4. Click Add… to add a repository.

5. Set Name to GEMMA Repository and URL to:

   https://gemma-plugin.vercel.app/gemma.xml

6. Click OK, then click Reload All Repositories.

7. Go to the All tab, search for GEMMA, and click Install Plugin.

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Method 2: Install from ZIP

1. Download the latest release from the GitHub Releases page.
2. Open QGIS.
3. Go to Plugins → Manage and Install Plugins.
4. Select the Install from ZIP tab.
5. Click Browse and select the downloaded gemma-plugin-v*.zip file.
6. Click Install Plugin.

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Verify Installation

After installation, verify that everything is working:

1. Check the Gemma menu in the menu bar — you should see submenus for Updating of Boundaries, EA Delineation, and Others.
2. Open the Processing Toolbox (Ctrl+Alt+T) and look for the GMD Pipeline group — you should see all the tools listed there.
3. The Gemma Toolbar should display icons for Check and Update, Create Enumeration Areas, and Package for QField.

Plugin Structure

The GEMMA plugin organizes its tools into the following categories:

Processing Toolbox — GMD Pipeline

These tools are accessible from the QGIS Processing Toolbox under the GMD Pipeline provider:

Tool	Description
MBI Checker	Detect gaps and overlaps in barangay boundaries
Fill Polygon Gaps	Fill gaps between polygon boundaries
Export Preliminary Polygons	Merge and export resolved boundary layers
Update LGU PSGC Metadata	Auto-populate PSGC metadata fields
Fix LGU CRS	Batch-correct local grid coordinates (~0 to ~100,000) to EPSG:4326
Join Barangay Attributes	Match vector attributes with official PSGC tables via fuzzy matching and Roman numeral normalization
Scan Geometry Errors	Scan polygon layers for specific geometry and topology defects and generate a Point Error Layer
Repair Polygon Geometries	Reconstruct invalid polygon geometries and recover missing shapes into a clean vector output layer
Clip Project Layers by Extent	Batch clip multiple vector layers to a target administrative polygon boundary with optional buffer

Gemma Menu — Updating of Boundaries

Tool	Access
Check and Update	Gemma → Updating of Boundaries → Check and Update

Gemma Menu — EA Delineation

Tool	Access
Create Enumeration Areas	Gemma → EA Delineation → Create Enumeration Areas

Gemma Menu — Others

Tool	Access	Shortcut
Package for QField	Gemma → EA Delineation → Package for QField	Ctrl+Alt+Q
Geometry Repair Toolkit	Gemma → Others → Geometry Repair Toolkit	—

Updating the Plugin

• Repository Install: QGIS automatically checks for updates on launch. Navigate to Plugins → Manage and Install Plugins → Upgrade All.
• ZIP Install: Download the latest ZIP and re-install via Install from ZIP to overwrite the previous version.

Changelog

For version history and detailed release notes, check our dedicated Changelog Page or visit GitHub Releases.

Support

For bug reports and feature requests, please use the GitHub Issues page.

For direct support, contact the GMD team at gmd.support@psa.gov.ph.