Modeling REDD-baselines using IDRISI’s LCM- Step 1

Analyzing Change

The first stage of a REDD project is the understanding of the historical trends in landuse change. The Change Analysis tab provides a set of tools for the rapid assessment of change, allowing one to generate a series of evaluations of gains and losses, net change, persistence and specific transitions both in map and graphical form. For the change and prediction analyses, a minimum requirement is the specification of two landcover maps that can be used as the basis of understanding the nature of change in the study region and the means of establishing samples of transitions that should be modeled. Other essential files associated with the study area are also specified: reference area, basis roads, and elevation.

Figure 1. Illustrates the historical pattern of change between three dates in time of the Ankeniheny-Mantadia Corridor in Madagascar.

The Change Analysis panel provides a series of very useful graphs of change between the two maps specified in the Project Parameters panel. One can view these graphs in a variety of units (cells, hectares, square kilometers, acres, square miles, % of change and % of area). This rapid assessment allows for an understanding of the dynamic of change among the different landuse categories of the two time periods.

With a greater understanding of the historical changes, the Change Maps panel provides the ability to create a spatial representation of the historical change, including maps of persistence, gains and losses, transitions and exchanges.