Welcome to the wiki of the Global Agro-ecological Zoning (GAEZ v5)

Global Agro-ecological Zoning (GAEZ v5) Model Documentation

The 2030 Agenda for Sustainable Development puts a strong emphasis on an integrated approach to achieving Sustainable Development Goals (SDGs) that can harness synergies and minimize potential trade-offs. Agriculture systems worldwide must become more productive and less wasteful. Sustainable agricultural practices and food systems, including both production and consumption, must be pursued from a holistic and integrated perspective. The sustainable use of land resources, notably in agriculture, can play an important role in accelerating the achievement of many SDGs. More innovations and coordinated efforts are needed to sustainably improve the global supply chain, decrease food losses and waste, and ensure that all who are suffering from hunger and malnutrition have access to safe and nutritious food. The current trajectory of growth in agricultural production is unsustainable because of its negative impacts on natural resources and the environment. One-third of farmland is degraded, up to 75% of crop genetic diversity has been lost and 22% of animal breeds are at risk. Land, water, healthy soils and plant genetic resources are key inputs into food production, and their growing scarcity in many parts of the world with increased environmental challenges, such as climate change, make it imperative to use and manage them sustainably.

An integrated decision-making process at national and regional levels is needed to achieve synergies and adequately address trade-offs in land use, water allocation and climate mitigation measures to avert conflicts among agriculture, energy production and climate change mitigation. Even though traditional knowledge can address some of the challenges at community scale, the full spectrum of available farming possibilities at national, regional and global levels is not known. Little technological means and few comprehensive information systems are available to support well-informed plans or implementation of strategies. The Agro-Ecological Zones (AEZ) methodology is a successful approach used in land evaluation to support sustainable agricultural development. AEZ relies on well-established land evaluation principles to assess natural resources for identifying suitable agricultural land utilization options. It identifies resource limitations and opportunities based on plant eco-physiological characteristics, climatic and edaphic requirements of crops and it uses these for evaluating suitability and production potentials for individual crop types under specific input and management conditions. Managing the constraints imposed by agro-ecological conditions and knowing what the most viable crop options are, can facilitate planning decisions and induce choices that, while more productive, are sustainable and resilient to climatic variability.

The Food and Agriculture Organization of the United Nations (FAO) and the International Institute for Applied Systems Analysis (IIASA) have cooperated over several decades to develop and implement the AEZ modelling framework and databases. Both FAO and IIASA have been employing AEZ for evaluating land utilization potentials of natural resources in numerous assessments at global, regional and national scales. The AEZ methodology was initially implemented in the 1980s to assess the capacity of the world's natural resources to meet the needs of a fast-growing global population, particularly in developing countries. Rapid developments in computing and geo-information technology have produced increasingly detailed global databases and IT resources, which made possible the first global AEZ assessment in 2000 (GAEZ v1). Since then, Global AEZ assessments have released in 2002 (GAEZ v2), in 2012 (GAEZ v3), and 2021 (GAEZ v4).

The current version of GAEZ v5 provides a further update of input data and extension of the methodology. It estimates sustainable crop production potentials for historical, current and future climatic conditions, comprising of several terabytes of spatial data at 5 arc-minutes (about 9 x 9 km at the equator). Production potentials are assessed for various (sustainable) levels of inputs and field management under rain-fed and irrigation water supply systems for several thousand combinations of crop-type, management level, water supply source and time period. Additionally, GAEZ v5 has produced a spatial representation of current agricultural production statistics (FAOSTAT) for year 2020. This database provides a complete spatial representation of current crop areas, yield and production for 33 major crop groups. By linking the actual crop production with corresponding spatial crop potentials, FAO and IIASA achieved unique global estimates of current (year 2020) yield and production gaps.

This model system documentation provides updated information on the GAEZ v5 methodological structure and describes the conceptual framework of individual assessment modules in ten chapters. Model input parameters and additional technical information are provided in appendices. The document will also support users accessing GAEZ v5 through the new GAEZ v5 Data Portal (https://data.apps.fao.org/gaez/). This Model Documentation is specifically recommended for AEZ modelers and users such as researchers and planners at national and international research institutes and multilateral organizations dealing with sustainable utilization of land resources, agricultural development and food security.

Citation

FAO & IIASA. 2025. Global Agro-ecological Zoning version 5 (GAEZ v5) Model Documentation. https://github.com/un-fao/gaezv5/wiki

Acknowledgements

The work on the Global Agro-Ecological Zoning version 5 (GAEZ v5) would not have been possible without the dedicated work of Günther Fischer, Harrij van Velthuizen, and Sylvia Tramberend from IIASA; Freddy Nachtergaele; and Federica Chiozza, Matieu Henry, and Livia Peiser from FAO. Special thanks to Dario Spiller, Rutendo Mukaratirwa, Shahla Asgharinia, and Filippo Sarvia from the Geospatial Unit of the Land and Water Division for their invaluable support. At FAO, we are also grateful for the support provided by colleagues from the Land and Water Division, particularly Michèle Piraux and James Morgan; and Gianluca Franceschini, Patrizia Monteduro, Daniele Conversa, and Karl Morteo from the Digital FAO and Agro-Informatics Division. The authors wish to thank all those who provided feedback and insights throughout the GAEZ v5 meetings and consultations over the years, helping to enhance land evaluation and refine the GAEZ methodological framework.

Abbreviations and acronyms

Acronym	Description
AEZ	Agro-Ecological Zones
AWC	Available soil Water Capacity
CMIP6	Coupled Model Inter-comparison Project Phase 6
DEM	Digital Elevation Model
ESM	Earth System Model
ETa	Actual evapotranspiration
ETm	Maximum evapotranspiration
ETo	Reference evapotranspiration
FAO	Food and Agriculture Organization of the United Nations
Fm	Modified Fournier Index
GAEZ	Global Agro-ecological Zones
HI	Harvest index
HWSD	Harmonized World Soil Database
IIASA	International Institute for Applied System Analysis
IPCC	Intergovernmental Panel on Climate Change
ISI-MIP	Inter-Sectoral Impact Model Inter-comparison Project
KBA	Key Biodiversity Areas
LAI	Leaf Area Index
LCCS	Land Cover Classification System
LGP	Length of Growing Period
LGPt5	Temperature Growing Period
LGPt10	Frost Free Period
LUTs	Land Utilization Types
NPP	Net Primary Production
P/ETo	Moisture Availability Index
RCPs	Representative Concentration Pathways
SOLAW	Status of Land and Water Resources for Food and Agriculture
SQ	Soil Quality
SRTM	Shuttle Radar Topography Mission
SSPs	Shared Socio-economic Development Pathways
WDPA	World Database of Protected Areas
WDe	Water Deficit