HR: 0800h
AN: B41A-0169    [Abstracts]
TI: Quantifying Forest Cover Change in Paraguay Using Data From Different Landsat Instruments
AU: * Kim, S
EM: sunghee@wam.umd.edu
AF: Global Land Cover Facility, Institute for Advanced Computer Studies, University of Maryland, 3166 A.V.Williams Building, College Park, MD 20742 United States
AU: * Kim, S
EM: sunghee@wam.umd.edu
AF: Department of Civil and Environmental Engineering, University of Maryland, 1173 Glenn L. Martin Hall, College Park, MD 20742 United States
AU: Townshend, J R
EM: jtownshe@geog.umd.edu
AF: Global Land Cover Facility, Institute for Advanced Computer Studies, University of Maryland, 3166 A.V.Williams Building, College Park, MD 20742 United States
AU: Townshend, J R
EM: jtownshe@geog.umd.edu
AF: Department of Geography, University of Maryland, 2181A Lefrak Hall, College Park, MD 20742 United States
AU: Altstatt, A
EM: aaltstat@hermes.geog.umd.edu
AF: Department of Geography, University of Maryland, 2181A Lefrak Hall, College Park, MD 20742 United States
AU: Huang, C
EM: cqhuang@umd.edu
AF: Global Land Cover Facility, Institute for Advanced Computer Studies, University of Maryland, 3166 A.V.Williams Building, College Park, MD 20742 United States
AU: Huang, C
EM: cqhuang@umd.edu
AF: Department of Geography, University of Maryland, 2181A Lefrak Hall, College Park, MD 20742 United States
AU: Song, K
EM: kuan@geog.umd.edu
AF: Global Land Cover Facility, Institute for Advanced Computer Studies, University of Maryland, 3166 A.V.Williams Building, College Park, MD 20742 United States
AU: Song, K
EM: kuan@geog.umd.edu
AF: Department of Geography, University of Maryland, 2181A Lefrak Hall, College Park, MD 20742 United States
AU: Davis, P
EM: pdavis@umiacs.umd.edu
AF: Global Land Cover Facility, Institute for Advanced Computer Studies, University of Maryland, 3166 A.V.Williams Building, College Park, MD 20742 United States
AU: Davis, P
EM: pdavis@umiacs.umd.edu
AF: Department of Geography, University of Maryland, 2181A Lefrak Hall, College Park, MD 20742 United States
AU: Rodas, O
EM:
AF: Guyra Paraguay, Coronel Rafael Franco 381 c/ Leandro Prieto, Casilla de Correos 1132, Asuncion, CTR N/A Paraguay
AU: Yanosky, A
EM:
AF: Guyra Paraguay, Coronel Rafael Franco 381 c/ Leandro Prieto, Casilla de Correos 1132, Asuncion, CTR N/A Paraguay
AU: Clay, R
EM:
AF: Guyra Paraguay, Coronel Rafael Franco 381 c/ Leandro Prieto, Casilla de Correos 1132, Asuncion, CTR N/A Paraguay
AB: During the last 30 years, Paraguay underwent massive changes in the forest cover. Changes include the removal of the majority of the interior Atlantic Forest, an ecosystem with the highest levels of recorded biodiversity. This study quantified three decades of forest cover (FC) change in Paraguay using Landsat data. To assess FC change between the 1990s and 2000s, wall-to-wall mapping was performed, using data from Landsat TM and ETM+ instruments. Multispectral and multitemporal data were integrated into an unsupervised clustering process. Procedures were developed and implemented automatically to assign meaningful class labels to individual spectral clusters, substantially reducing human input. The accuracy assessment on the thematic map of FC in the 2000s was performed by examining aerial photos and the fine-resolution imagery. Overall accuracy on sampled populations was 0.9512 on average at a 95% confidence level. It indicates that the method used in this study is highly reliable in dealing both with data acquired at different times and with data from different Landsat instruments. Because of the differences in spatial and spectral-resolution between Landsat MSS and TM data, FC change between the 1970s and 1990s was estimated by assessing FC from each epoch using a different approach. FC for the 1970s was obtained by applying a statistical sampling method to the MSS imagery. Ecoregion-based stratified systematic sampling was utilized to select samples in every spatial interval of 0.15 degree in both the latitude and longitude directions. This method yielded 342 samples within the Atlantic Forest region. Each of 9 MSS pixels in individual samples was interpreted as forest or non-forest, which allowed the calculation of the percentage of FC within a given sample. When the method was applied to TM imagery for 1990s, the two methods, mapping and sampling, yielded almost identical results for the 1990 epoch. FC change between the 1970s and 1990s was calculated by differencing FC between the two epochs. The results show that the extent and spatial patterns of FC change in two main ecoregions, the Chaco and Atlantic Forest are considerably different. Between the 1990s and 2000s, 6.42% of the initial 134,400 km² of the Chaco was lost, while the initial 34,800 km² of the Atlantic forest was reduced by 38.9%. Within the Atlantic Forest region, the total area of 85,500 km² was forested by 73.4% in the 1970s. The forest area was reduced by 40.7% during the 1990s. By the 2000s, only 24.8% of the total region was forested. Although most protected areas experienced little change within their borders, buffer zones were deforested at an alarming rate. For instance, a well-managed reserve, Mbaracayu National park suffered from 40.0% of the initial forest loss from 400 km² to 240 km² in a 5 km buffer zone between the 1990s and 2000s.
DE: 1694 Instruments and techniques
SC: Biogeosciences [B]
MN: Fall Meeting 2005