Substrate mobility measures the realized mobility of the physical substrate, due to both substrate composition (i.e. sand) and exposure to forces (wind and water) that transport material. This is an important attribute of certain dynamic systems (e.g., coastal dune systems) and is given as an index of mobility (1=stable , 10=highly mobile, values 6, 7, 8, and 10 do not occur in the Northeast region). Substrate mobility was derived from a custom algorithm based on the ESMplus and National Land Cover Database (NLCD) classes and National Wetlands Inventory (NWI) polygons.