Estimates of subsurface tile drainage extent for the conterminous United States, early 1990s

This dataset is a 30-meter resolution national-scale raster of estimated subsurface tile drainage extent based on early 1990s county areas of subsurface tile drains...本数据集为基于20世纪90年代初期县域地下暗管排水面积数据，构建的30米空间分辨率国家级尺度地下暗管排水分布范围估算栅格数据集。