Modeling deforestation baselines using GEOMOD - Instituto ...

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Finalizing Avoided Deforestation Baselines Low Risk High Risk Figure 6. Map showing relative risk of deforestation across the Campeche region based on analysis of empirical areas of deforestation versus 13 spatially explicit candidate driver maps. Black (class 0) represents areas already deforested in 2000, or water. Winrock International A- 18
Finalizing Avoided Deforestation Baselines Figure 7. Risk of deforestation (Figure 7) condensed into 3 classes, high, medium and low based solely on effectiveness of a combination of drivers in predicting the validation landscape. No deforestation rate factor is incorporated in this schematic. IV. D. Derivation of land clearing rate To model land-use change spatially over time there must be empirical evidence of change in a region. We used imagery for only a 5-year time period (Figure 8) because 1) it was the most spatially congruent data set available, 2) it is the highest resolution data set available, and 3) we invested in the creation of the year 2000 classification to the same level as the 1995 to have two maps that used the same classes. Both were based on a training set provided by Ron Eastman, Chair of the Geography Department, Clark University. To determine the deforestation/degradation pathway we created two land use classes (Figure 9). Agriculture, pasture and urban were already lumped in the 1995 classification. To this we added savanna, which generally is not found in the region naturally (INEGI 2000). Our own analysis shows land classified as ‘savanna’ returning to forest in 5 years, indicating it was pasture; it is often difficult to discriminate savanna from pasture in the classification process. The 1995 and 2000 images show different quantities of forest degradation depending on whether one includes secondary vegetation in the forested or deforested category (Figure 9). More than 395,000 ha of selva alta were converted to selva baja between 1995 and 2000, while another 31,000 ha were converted to secondary vegetation (Table 6). Determining the ‘from’ carbon pool and the ‘to’ carbon pool, when only two pools are allowed by the model at a time is complicated by these factors and the various pathways are illustrated in Figure 9. Including secondary vegetation in the Winrock International A- 19
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