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US/MEXICO STUDY: NALC/MEXICO LAND COVER MAPPING RESULTS-IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITIONS
Citation:
Lyon, J G. US/MEXICO STUDY: NALC/MEXICO LAND COVER MAPPING RESULTS-IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITIONS. Presented at Monitoroing Science & Technology Symposium, Denver, CO, September 20-24, 2004.
Impact/Purpose:
The overall objective of this task is to provide the Agency with improved science guidance and strategies for more effective science management and administration.
Description:
An inventory of land-cover conditions throughout Mexico was performed using North American Landscape Characterization (NLAC) Landsat Mult-Spectral Scann (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and 1990s epoch periods. The equivalents of 300 image scenes were analyzed using an unspupervissed classification approach by a consortium of 13 universities and institutes across Mexico. Accuracy assessments were the conducted to validate the 1970s and 1990s results using independent land-cover classifications (reference data) developed from the interpretation of 1:100,000 scale aerial photography collected in 1973, and Landstat Thematic Mapper (TM) imagery collected between 1990 - 1993. The 1980s epoch classifications were compared to both reference datasets, collectively. The relative accuracy of the classifications results was 60% for both the 1970s and 1990s epoch and 67% for the 1980s epoch. The significantly (p = 0.05) higher accuracy for 1980s epoch (67%) was thought to be an aberration resulting from the combined application of two reference datasets, resulting in a random compensation of reference data error.An inventory of land-cover conditions throughout Mexico was performed using North American Landscape Characterization (NLAC) Landsat Mult-Spectral Scann (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and 1990s epoch periods. The equivalents of 300 image scenes were analyzed using an unspupervissed classification approach by a consortium of 13 universities and institutes across Mexico. Accuracy assessments were the conducted to validate the 1970s and 1990s results using independent land-cover classifications (reference data) developed from the interpretation of 1:100,000 scale aerial photography collected in 1973, and Landstat Thematic Mapper (TM) imagery collected between 1990 - 1993. The 1980s epoch classifications were compared to both reference datasets, collectively. The relative accuracy of the classifications results was 60% for both the 1970s and 1990s epoch and 67% for the 1980s epoch. The significantly (p = 0.05) higher accuracy for 1980s epoch (67%) was thought to be an aberration resulting from the combined application of two reference datasets, resulting in a random compensation of reference data error.