Estimates of Subsurface Tile Drainage Extent for 12 Midwest States, 2012

This dataset is a 30-meter resolution raster of estimated extent of subsurface tile drainage developed from tabular data of state-level estimates of agricultural land drained by tiles combined with geospatial cropland and soils in 12 Midwest States (SD,NE, KS, MN, IA, MO, WI, IL, MI, IN, OH, and KY). This dataset was created from the following four sources: 1) state-level acreages of agricultural "land drained by tiles" from the 2012 Census of Agriculture (U.S. Department of Agriculture, 2015a); 2) the extent of cultivated cropland from the National Land Cover Dataset (NLCD) 2011 (Homer and others, 2015; U.S. Geological Survey, 2014a); 3) the extent of poorly and moderately drained soils from the State Soil Geographic Database (STATSGO) database Version 2 (U.S. Department of Agriculture, 2006); and 4) state administrative boundaries (U.S. Geological Survey, 2014b). The area of drained land was evenly allocated to potentially drained land for agriculture - cropland with poorly drained soil - except in Iowa. For Iowa, because the reported area of land drained by tiles exceeded the area of cropland on poorly drained soils, the additional area of subsurface tile drains above the area of cropland on poorly drained soils was assigned to land characterized as cropland with moderately drained soil. The estimated extent of subsurface tile drains in each cell is expressed in square meters.