Attributes for NHDPlus Version 2.1 Flowlines for the Conterminous United States: Percent of Agriculture Land Subject to Select National Resource Inventory Conservation Practices, 2000-2012

This metadata record describes 24 tabular data sets that estimate the percent of agricultural land that may be subject to select conservation practices for each year during the period 2000-2012 compiled for two spatial components of the NHDPlus version 2.1 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2018). The data were derived from Percent of Agriculture Land Subject to Select National Resource Inventory (NRI) Conservation Practices, 2000-2012 (Wieczorek, 2019). One set of tables (denoted by the Impv prefix) represents an estimate of the percent of agricultural land potentially subject to Alley Cropping, Contour Buffer Strips, Contour Farming, Contour Orchard/Other Fruit Area, Cross Wind Trap Strips, Field Border, Filter Strip, Grassed Waterway, Hedgerow Planting, Herbaceous Wind Barriers, Irrigation System, Tailwater Recovery, Riparian Forest Buffer, Stripcroppings, Terrace, Tree/Shrub Establishment, and Windbreak/Shelterbelt Establishment practices. The other set (denoted by the Wrse prefix) represents the estimated percent of agricultural land potentially subject to Bedding, Hillside Ditch, Surface Drainage, Field Ditch, and Water and Sediment Control Basin practices. These grouped practices were then processed into 24 separate national tables (12 years x 2 practice types) as described in the process steps of this metadata record. These conservation practice data are estimated areas subject to a conservation practice and not an actual conservation practice footprint. Summaries that could possibly reveal the location and/or identity of an NRI sample site may not be published.