Good evening from India!
Agro-ecological zoning separates areas into the region at the apex level and agro-eco unit at the bottom. The agro-ecological region identifies the natural resources in terms of problems, potentialities and constraints and their extent with respect to land utilization types and groups them in uniform units. Digital database in GIS and application of logic through decision support system (DSS) further enhance the process and precession of agro-ecological delineation. The sub agro ecological regions are further subdivided into agro-ecological zones based on landforms, soil association and land use. The agro ecological zones have further taken down to sub zones depending on terrain characteristics, parent materials, soil texture, depth, salinity, surface and ground water potentiality and cropping pattern.
Also we may think for overlaying vulnerability map with such agro ecological zones to create polygons in GIS and use the same to predict food security as well as systems need to be followed in long run for food sustainability.
With warm regards,