resolution was obtained from the Earth Resource Observation and Sciences (EROS) of the USGS.
The land-cover data were generated to simulate three separate temporal periods for the study area for use in the Soil and Water Assessment Tool (SWAT) models. The three temporal periods represent: 1970 - 1989, 1990 - 1999, and 2000 - 2009. Land Use and Land Cover (LULC) is historical data derived from USGS aerial photography taken during the 1970s - 1980s period. The National Land Cover Dataset (NLCD) 1992 was created in the early 1990s using Landsat Thematic Mapper (TM) data. The NLCD2001 is based on the early 2000s Landsat Enhanced Thematic Mapper+ (ETM+) data. The NLCD2001 has been updated in the version NLCD2006 using the Landsat ETM+. The land-cover data sets have different sub-category legends used in the classification. To maintain land-cover classification consistency the land-cover data are reclassified into the following seven classes: (1) grass, (2) bush/shrub, (3) forest, (4) developed land, (5) barren land, (6) water, and (7) crop land. The developed land is defined as areas where constructed materials, such as asphalt, concrete and buildings, account for greater than 30% of the total cover (Wickham et al. 2004). The land-cover change comparison is applied to quantitatively detect aerial change in land-cover class (i.e., which land-cover class is changing to the other type of land-cover class). This process
resolution was obtained from the Earth Resource Observation and Sciences (EROS) of the USGS.The land-cover data were generated to simulate three separate temporal periods for the study area for use in the Soil and Water Assessment Tool (SWAT) models. The three temporal periods represent: 1970 - 1989, 1990 - 1999, and 2000 - 2009. Land Use and Land Cover (LULC) is historical data derived from USGS aerial photography taken during the 1970s - 1980s period. The National Land Cover Dataset (NLCD) 1992 was created in the early 1990s using Landsat Thematic Mapper (TM) data. The NLCD2001 is based on the early 2000s Landsat Enhanced Thematic Mapper+ (ETM+) data. The NLCD2001 has been updated in the version NLCD2006 using the Landsat ETM+. The land-cover data sets have different sub-category legends used in the classification. To maintain land-cover classification consistency the land-cover data are reclassified into the following seven classes: (1) grass, (2) bush/shrub, (3) forest, (4) developed land, (5) barren land, (6) water, and (7) crop land. The developed land is defined as areas where constructed materials, such as asphalt, concrete and buildings, account for greater than 30% of the total cover (Wickham et al. 2004). The land-cover change comparison is applied to quantitatively detect aerial change in land-cover class (i.e., which land-cover class is changing to the other type of land-cover class). This process
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