Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States: Herbicide Use on Agricultural Land in Kilograms per square Kilometer, 2009

This data set represents the Herbicide use on agricultural land in kilograms per square kilometer, 2009 value 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 network (i.e., watersheds). This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data were produced by Baker, N.T., 2015. Units for the Herbicide use on agricultural land in kilograms per square kilometer, 2009 are kilogram per square kilometer. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river networks 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, 2016).