Foodshed Analysis

Not directly. A foodshed analysis maps where a population's food could come from given the surrounding production capacity and a proximity-based allocation rule — it is a model of biophysical potential, not a record of real trade flows. Actual sourcing is governed by markets, prices, contracts and infrastructure that the standard model abstracts away. The delineated foodshed and self-sufficiency ratio therefore answer 'how much could be supplied locally, and from where', which is exactly the planning and feasibility question, but they should not be read as describing the food that is in fact shipped to the city today.

Strongly. Because demand is computed from a reference diet, the assumed eating pattern changes how much food, and which types, the population needs, and therefore how much local land can cover. A more plant-based diet generally requires less land per person and raises self-sufficiency, while a meat-heavy diet lowers it. This is why foodshed analysis is run as a scenario tool: varying the diet (and yields and boundaries) reveals how sensitive localization potential is to these choices. Reporting a single self-sufficiency figure without stating and testing the diet assumption would misrepresent the analysis.

It borrows the watershed's spatial logic. A watershed is the land area that drains to a particular water body; a foodshed is the land area capable of supplying food to a particular population centre. Both are defined by flows across space converging on a point — water by gravity and terrain, food by allocation from capable land to demand. The analogy motivates the proximity-based allocation at the method's core: just as water comes from the surrounding drainage area, food in the model is drawn first from the nearest productive land, with the resulting catchment delineated as the foodshed.