Modeling the spatial pattern of land-use change with GEOMOD2: application and validation for Costa Rica

The objective of this paper is to simulate the location of land-use change, specifically forest disturbance, in Costa Rica over several decades. This paper presents a GIS-based model, GEOMOD2, which quantifies factors associated with land-use, and simulates the spatial pattern of land-use forward and backward in time. GEOMOD2 reads rasterized maps of land-use and other biogeophysical attributes to determine empirically the attributes of land that humans tend to use. Then GEOMOD2 uses the patterns of those biogeophysical attributes to simulate the spatial pattern of land-use change. GEOMOD2 can select locations for land-use change according to any of three decision rules based on (1) nearest neighbors, (2) stratification by political sub-region, and/or (3) the pattern of biogeophysical attributes. GEOMOD2 simulates the progressive loss of closed-canopy forest in Costa Rica for 1940, 1961 and 1983, which are the years for which maps of land-use are available. Also, GEOMOD2 extrapolates the pattern of land-use to the year 2010. When GEOMOD2 extrapolates land-use change over several decades, it is able to classify correctly between 74 and 88% of the grid cells, for two categories: forest versus non-forest. Over various simulation runs, Kappa ranges from 0.31 to 0.53. The model's ability to predict the location of disturbance is best when the model is driven by the location of biogeophysical characteristics, most importantly lifezones. (C) 2001 Elsevier Science B.V. Ah rights reserved.