1. SEReGAP Land Cover Mapping Summary and Results Southwest Regional GAP Project Arizona, Colorado, Nevada, New Mexico, Utah US-IALE 2004, Las Vegas, Nevada: Transdisciplinary Challenges in Landscape Ecology R. Douglas Ramsey, John Lowry, Jessica Kirby, Wendy Rieth, Lisa Langs Remote Sensing and GIS Laboratory Utah State University Logan, Utah

4. 1995 GAP 30 M2003 GAP 30 M1995 GAP 100 Ha

5. Edgematching

9. ACCURACY ASSESSMENT Accuracy assessment is based on a 20% sample of training sites for each mapped type. Since the 20% sample is not independent, this is not considered a true accuracy assessment. The 20% sample or validation set is not used in the classification tree model development. In addition to a validation with a 20% sample, we have supported our findings with a manual 5-fold cross validation with sample replacement to test model stability and help understand the effects of validation sample size on the model stability results.

10. Each site is considered correctly classified if the majority of pixels agree with sample polygon

11. Validation: Lower Wasatch Range MZ

12. Overall Accuracy: 65% - 24 types Kappa: 0.61 Standard error of kappa: 0.01 Z-Score for kappa: 46.73 Accuracy for Mapping Zone UT04

13. Accuracy for Mapping Zone UT02 Overall Accuracy: 69% - 51 types

14. Overall Accuracy: 60% - 32 types Kappa: 0.56 Standard error of kappa: 0.008 Z-Score for kappa: 66.61 Accuracy for Mapping Zone UT03

15. Summary Statistics, 5-fold Validation This is a 5-fold cross validation with sample replacement to test model stability and help understand the effects of validation sample size on the model stability results.

16. Sample Size vs Accuracy and Coefficient of Variation

17. % of area mapped vs. available sample size (Great Salt Lake Desert)

18. % of area mapped vs. accuracy level

19. < 20 samples > 20 samples > 40 samples

20. Conclusions Current validation shows between 60-65% “accuracy” for completed mapping zones. Variance of accuracies is directly linked to validation sample size. A validation set of 40 points seems to provide some stability to model results. A minimum of 40 samples for validation per cover type should be a target size. This is difficult due to the preponderance of “rare” types and the lack of training sites. Using a 20% validation set, we need a minimum of 200 field sites per mapped type. This is difficult given the availability of unique sample sites for a particular cover type. Overall map “accuracy” seems to coincide with expected results given the map detail. Rare ecological systems and systems that consist of a wide range of cover types (I.e. shrub steppe types) tend to lower accuracies.

21. Acknowledgements