Summary

Description

This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CP464), Irrigation Land Leveling (ILL) on agricultural land by county. Irrigation Land Leveling is described as "[r]eshaping the surface of land to be irrigated to planned grades...for the purpose of permitting uniform and efficient application of irrigation water to the leveled land." (U.S. Department of Agriculture, 1995) This data set was created with geographic information systems (GIS) and database management tools. The acres on which ILL's are applied were totaled at the county level in the tabular NRI database and then apportioned to a raster coverage of agricultural land within the county based on the Enhanced National Land Cover Dataset (NLCDe) 1-kilometer resolution land cover grids (Nakagaki, 2003). Federal land is not considered in this analysis because NRI does not record information on those lands.