This method maps levels of risk of flooding and stream mobility. Overlaying these two graded maps creates a "Freedom Space" map with three levels of risk and aims to combine inundation and erosion mapping on a reach or a watershed scale.
"Mobility Space" is calculated using migration rates determined from historical maps and photos, vegetation and soil data to estimate bank and floodplain erodibiity, and topogaphy to determine valley edges.
"Flood Space" is mapped based on field assessment of morphologic evidence and desktop assessment of topographic evidence of flood susceptibility, as well as through assessment of wetland maps.
Two levels of mobility (50-years and "floodplain") and three levels of flooding (high, medium, low) are determined and joined to create a three-tiered map of "Freedom Space" (minimum, functional, rare).
Biron, et al., 2014. Freedom Space for Rivers: A Sustainable Management Approach to Enhance River Resilience. Environmental Management 54, pp. 1056-1073
Note that figure above is taken for this article.