ICAM: An Iterative Cost‑based Spatial Accessibility Model for Supply–Demand Allocation

Tool from research article Ala-Hulkko, T., Toivanen, M., Poturalska, A., Magyar, M., Kinnunen, P., and Kotavaara, O. (2026). Global accessibility of food ecosystem services under economic inequality, food production, and infrastructure shocks, Journal of Cleaner Production (accepted).

ICAM: An Iterative Cost‑based Spatial Accessibility Model for Supply–Demand Allocation

ICAM is a GIS-based analytical tool developed for network-based supply–demand allocation within defined catchment areas. ICAM iteratively allocates supply to demand locations along least-cost paths within a transport network, starting from the lowest cost-distance and continuing until a user-defined transport cost threshold is reached. The framework quantifies both supply surplus and unmet demand, enabling the assessment of spatial accessibility under different cost and network conditions.

The tool supports two analytical variants: equal-cost (EQ) analysis, assuming uniform transport costs across the network, and expenditure-adjusted (EX) analysis, which incorporates demand-side expenditure ratios into the cost structure to reflect economic access constraints. Both variants follow the same iterative allocation logic but differ in the ordering of cost-distance relationships.

ICAM is implemented using ArcGIS Pro (Network Analyst) and Python, and can be executed within the ArcGIS Pro environment. The tool enables the analysis of accessibility dynamics under varying infrastructure configurations, production patterns, and cost scenarios, including economic disparities and transport disruptions.

Tool includes ArcGIS Pro script tool in a toolbox and the associated Python script.