Attributes for NHDPlus Version 2.1 Catchments and Modified Routing of Upstream Watersheds for the Conterminous United States:  Estimated Area of Subsurface Drainage on Agricultural Land, 1992
This tabular data set represents the estimated percent area of subsurface drainage for the year 1992 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 through the river …