Combining accuracy assessment of land-cover maps with environmental monitoring programs

A scientifically valid accuracy assessment of a large-area, land-covet map is expensive. Environmental monitoring programs offer a potential source of data to partially defray the cost of accuracy assessment while still maint aining the statistical validity. In this article, three general strategies for combining accuracy assessment and environmental monitoring protocols ar e described. These strategies range from a fully integrated accuracy assess ment and environmental monitoring protocol, to one in which the protocols o perate nearly independently. For all three strategies, features critical to using monitoring data for accuracy assessment include compatibility of the land-cover classification schemes, precisely co-registered sample data, an d spatial and temporal compatibility of the map and reference data. Two mon itoring programs, the National Resources Inventory (NRI) and the Forest Inv entory and Monitoring (FIM), are used to illustrate important features for implementing a combined protocol.