FarmGML ADE 🚜

Application Domain Extension

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FarmGML is an Application Domain Extension (ADE) of CityGML 3.0, designed to represent rural enterprises, agricultural activities, and agro-environmental data consistent with digital twin semantics.

It allows the integration of agricultural and environmental information into structures compatible with 3D models, spatial databases, WebGIS platforms (CesiumJS), and agroclimatic analytics systems.

It extends CityGML classes (such as LandUse, Vegetation, and Building) to model:

• Rural properties and agricultural enterprises
• Crop areas, production cycles, and harvest lots
• Risk and sustainability indicators
• Integration with geospatial and remote-sensing data

FarmGML enables integration between 3D city models, agricultural information systems, QGIS, 3DCityDB, and CesiumJS for digital twins of rural areas.

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Table of Contents

• About the Project
• Modeled Features
• Version Information
• Validation Results
• Workflow (MDA)
• References
• Contact

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About the Project

The FarmGML ADE extends CityGML 3.0 to represent agricultural holdings (farms), crop areas, rural enterprises (livestock, aquaculture), agricultural operations, risk assessments (ZARC NM), and sustainability metrics.

This project follows the Model-Driven UML-to-XSD methodology and complies with the OGC CityGML 3.0 ADE design rules.

Modeled Features

FarmGML is divided into modules, including:

• Core (farm-core.xsd): Defines the main RuralProperty feature (based on luse:LandUse) and basic data types (Person, Household, Farm Profile).
• Enterprise (farm-enterprise.xsd): Models different enterprises such as LivestockEnterprise, AquacultureEnterprise, and ForestryEnterprise.
• Production (farm-production.xsd): Defines AnnualCropArea, PerennialCropArea (based on veg:PlantCover), and HarvestedLot.
• Operations (farm-operations.xsd): Models events over time (e.g., planting, harvesting) using AgriculturalOperation (based on dyn:AbstractDynamizer).
• Risk & Sustainability (farm-risk.xsd, farm-sustainability.xsd): Adds generic attributes for Risk (ZARC) and sustainability metrics (carbon footprint, etc.) via the core:genericAttribute hook.
• Temporal (farm-temporal.xsd): Enables TimeSlices for features (based on vers:AbstractVersion).

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🧩 Version Information

Field	Value
ADE Name	FarmGML
Version	1.3
Target Standard	OGC CityGML 3.0
Namespace URI	https://igorquintao.github.io/FarmGML-ADE/schemas/1.3
Schema Location	https://raw.githubusercontent.com/IgorQuintao/FarmGML-ADE/main/schemas/1.3/FarmGML.xsd
Prefix	farm
Last Updated	2025-10-31
License	Creative Commons Attribution 4.0 International (CC BY 4.0)

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🗂️ Repository Structure

FarmGML-ADE/
│
├── xsd/                  # FarmGML and modules (100% online)
│   ├── FarmGML_ADE_v1-3.xsd
│   │
│   └── modules/
│       ├── farm-core.xsd
│       ├── farm-hooks.xsd
│       ├── farm-enterprise.xsd
│       ├── farm-production.xsd
│       ├── farm-operations.xsd
│       ├── farm-risk.xsd
│       ├── farm-sustainability.xsd
│       ├── farm-temporal.xsd
│       └── farm-join.xsd
│
├── test_data/                  # Load the GML Test Data in QGIS
│   ├── example_ruralproperty.gml
│   ├── example_cropcycle.gml
│   ├── example_enterprise.gml
│   ├── examplo_macro_lod0_ruralproperty.gml
│   ├── examplo_meso_lod1_ruralproperty.gml
│   ├── v1_example_ruralproperty.gml
│   └── v2_example_ruralproperty.gml
│       
├── model/                  # UML/XMI source (conceptual model)
│   └── 1.3/
│       ├── FarmGML_v1.3.xmi
│       └── diagrams/
│
├── schemas/                # Generated schemas and examples (distribution 100% offline)
│   └── 1.3/
│       ├── FarmGML.xsd
│       ├── farm-core.xsd
│       ├── farm-hooks.xsd
│       ├── farm-enterprise.xsd
│       ├── farm-production.xsd
│       ├── farm-operations.xsd
│       ├── farm-risk.xsd
│       ├── farm-sustainability.xsd
│       ├── farm-temporal.xsd
│       ├── farm-join.xsd
│       │
│       ├── codelists/
│       │   ├── BuildingType.xml
│       │   ├── CropGrowthStage.xml
│       │   ├── EducationLevel.xml
│       │   ├── FeedingPractice.xml
│       │   ├── ForestryProductType.xml
│       │   ├── InputType.xml
│       │   ├── LandTenureType.xml
│       │   ├── MainLocationType.xml
│       │   ├── OperationType.xml
│       │   ├── RelationshipToHead.xml
│       │   ├── SeedVarietyType.xml
│       │   ├── Sex.xml
│       │   └── StorageType.xml 
│       │
│       ├── examples/
│       │   ├── example_ruralproperty.gml
│       │   ├── example_simp-ruralproperty.gml
│       │   ├── example_cropcycle.gml
│       │   └── example_enterprise.gml
│       ├── metadata/
│       │   └── farmgml-metadata.yaml
│       │
│       └── ogc/
│           ├── citygml/
│           │   ├── 3.0/
│           │   │   ├── core.xsd        
│           │   │   ├── landUse.xsd
│           │   │   ├── building.xsd
│           │   │   ├── vegetation.xsd
│           │   │   ├── generics.xsd
│           │   │   ├── dynamizer.xsd
│           │   │   └── versioning.xsd
│           │   └── xAL/
│           │       ├── xAL-types.xsd
│           │       └── xAL.xsd
│           │
│           └── gml/
│               └── 3.2.1/
│                   ├── gml.xsd
│                   └── xlinks.xsd
│
├── tools/                   # Automation and validation tools
│   ├── shapechange-config/
│   │   └── farmgml_1.3_config.xml
│   ├── scripts/
│   │   ├── generate-xsd-from-uml.bat
│   │   └── validate-xsd.sh
│   └── validation/
│       ├── validate_farmgml.py
│       ├── validate_report.html  
│       │
│       └── schematron/
│           └── farmgml_rules.sch
│
├── docs/                   # Documentation and policies
│   ├── specification/
│   │   ├── FarmGML_Conceptual_Model.pdf
│   │   ├── FarmGML_Encoding_Specification.pdf
│   │   └── FarmGML_UseCases.pdf
│   │
│   ├── schema-reference/
│   │   └── 1.3/
│   │       └── farmgml_rules.sch
│   │
│   └── policies/
│       └── namespace-policy.md
│
├── .ogc/                   # OGC submission metadata
│   ├── submission-manifest.yaml
│   ├── contact.json
│   └── ogc-registration.yaml
│
├── CHANGELOG.md
├── LICENSE.txt
└── README.md

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🧠 Schema Modules

Module	Description
farm-core.xsd	Defines the FarmGML core model (RuralProperty, LandUnit, FarmProfile, etc.)
farm-enterprise.xsd	Models rural enterprises, their legal and structural attributes
farm-production.xsd	Defines productive areas (AnnualCropArea, PerennialCropArea, Pasture, etc.)
farm-operations.xsd	Describes agricultural operations and temporal dynamizers
farm-risk.xsd	Structures for insurance, risk indexes, and ZARC indicators
farm-sustainability.xsd	Environmental and sustainability indicators
farm-temporal.xsd	Temporal modeling based on core:AbstractTimeSliceType
farm-hooks.xsd	ADE integration hooks for CityGML generic linkage

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First Validation and Conformance

Validation was performed using xmlschema 2.5.1 and Python 3.11 via the script tools/validation/validate_farmgml.py below:

import xmlschema
from pathlib import Path

XSD_PATH = Path("schemas/1.3/FarmGML.xsd")
EXAMPLES_DIR = Path("schemas/1.3/examples")

schema = xmlschema.XMLSchema(XSD_PATH)

print(f"✅ Loaded schema: {XSD_PATH}")
print("🔍 Validating examples...\n")

for gml in EXAMPLES_DIR.glob("*.gml"):
    try:
        schema.validate(gml)
        print(f"{gml} : OK ✅")
    except xmlschema.XMLSchemaException as e:
        print(f"{gml} : Error ❌ -> {e.reason}")

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✅ Validation Results

tools/validation/validate_report.html

GML File	Status
example_cropcycle.gml	✅ OK
example_enterprise.gml	✅ OK
example_ruralproperty.gml	✅ OK
example_simp-ruralproperty.gml	✅ OK

Conclusion:

All GML example files were successfully validated. The FarmGML.xsd schema is fully compliant with OGC CityGML 3.0 ADE and GML 3.2.1 standards.

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⚙️ Model-Driven Architecture (MDA) Workflow

FarmGML adopts a Model-Driven Architecture approach.
All schemas and documentation are generated from the UML conceptual model.

Workflow summary:

1. Model conceptual features in UML.
2. Export UML → XMI (model/1.3/FarmGML_v1.3.xmi).
3. Configure ShapeChange using tools/shapechange-config/farmgml_1.3_config.xml.
4. Run ShapeChange to generate XSD modules under schemas/1.3/.
5. Validate using the included validate-xsd.sh script.
6. Test instances (example_ruralproperty.gml) with 3DCityDB, CesiumJS, and QGIS.

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Validation and Use Cases

To validate the FarmGML ADE:

1. 3DCityDB

   • Import the CityGML 3.0 core schema and FarmGML ADE modules.
   • Load schemas/1.3/examples/example_ruralproperty.gml using the Importer/Exporter.
   • Confirm ADE tables are created (e.g., farm_ruralproperty, farm_croparea).
   • Visualize using the 3DCityDB Web Map Client or CesiumJS.

2. CesiumJS

   • Convert the database instance to 3D Tiles using 3DCityDB Exporter.
   • Publish tiles on a CesiumJS viewer.
   • Use the attributes from FarmGML (e.g., crop type, sustainability index) for pop-ups or layer styling.

3. QGIS

   • Load the GML directly via Layer → Add Layer → Add Vector Layer…
   • Ensure the CityGML 3.0 + ADE plugin is active.
   • Inspect feature attributes and geometry consistency.

Validation success criteria:

• All features are parsed without schema errors.
• The ADE-specific attributes (farm:) are recognized in each environment.

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📚 References

•	3DCityDB ADE Manager
•	CesiumJS (https://cesium.com/platform/cesiumjs)
•	Van den Brink, L., Stoter, J., Zlatanova, S. (2013) – UML-Based Approach to Developing a CityGML Application Domain Extension. Transactions in GIS, 17(6): 920–942.
•	OGC (2021) – CityGML 3.0 Conceptual Model Standard (OGC 20-010).
•	ISO 19136 – Geography Markup Language (GML).
•	ShapeChange Tool – UML-to-GML encoder implementing ISO encoding rules.

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👤 Contact

Name	Eng. Igor Quintão
Organization	UNIVERSIDADE FEDERAL DE VIÇOSA - UFV
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Email	[email protected]
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Version	FarmGML ADE v1.3
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Date	2025-10-25
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© 2025 FarmGML ADE Project — Licensed under CC BY 4.0

Developed using Model-Driven Architecture principles (UML → ShapeChange → XSD)

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🏛️ Namespace Ownership

The official namespace URI for this ADE is:

https://igorquintao.github.io/FarmGML-ADE/schemas/1.3

It is maintained by Eng. Igor Quintão under GitHub Pages hosting.
This URI resolves to the authoritative location of the FarmGML ADE schemas and documentation.