KDF Search Results

Nitrogen (N) is an important nutrient as it often limits productivity, but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flowpaths and biological transformations of N at the watershed scale.

Excess nutrients from agriculture in the Mississippi River drainage, USA have degraded water quality in
freshwaters and contributed to anoxic conditions in downstream estuaries. Consequently, water quality is a
significant concern associated with conversion of lands to bioenergy production. This study focused on the
Arkansas-White-Red river basin (AWR), one of five major river basins draining to the Mississippi River. The
AWR has a strong precipitation gradient from east to west, and advanced cellulosic feedstocks are projected to

The National Hydrography Dataset (NHD) and Watershed Boundary Dataset (WBD) are used to portray surface water on The National Map. The NHD represents the drainage network with features such as rivers, streams, canals, lakes, ponds, coastline, dams, and streamgages. The WBD represents drainage basins as enclosed areas in eight different size categories. The NHD is portrayed on the US Topo map product produced by the USGS and the NHD and WBD can be viewed on the Hydrography Viewer or the general mapping oriented The National Map Viewer.