Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States:  Estimates of Subsurface Tile Drainage Extent for the Conterminous United States, Early 1990s
This tabular data set represents the estimated percent area of subsurface tile drainage extent from the early 1990's compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream …