Philip Saksa1, Y.Jun Xu2, April Mason1, and Daniel L. Thomas3. (1) School of Renewable Natural Resources, Louisiana State University, Rm. 227, RNR Building, Baton Rouge, LA 70803, (2) School of Renewable Natural Resources, Louisiana State University Agricultural Center, 227 Renewable Natural Res Bldg, Baton Rouge, LA 70803, (3) Biological and Agricultural Engineering, LSU AgCenter, Baton Rouge, LA 70803
Headwater streams drain the majority of the landscape, and
knowledge of sediment transport from these systems is therefore critical in
protecting overall stream water quality.�
While many sediment studies have been performed in topographically variable
areas, such as the Pacific Northwest, little
information exists on headwater streams draining the coastal plains, including
streams on the Southeastern Gulf Coast Plain. A study on the hydrology and
water quality of this region has been established in the Flat Creek Watershed,
located within the Ouachita River Basin of North Central Louisiana.� Flat Creek is a flat, lowland watershed (369
km2) dominated by commercially forested loblolly pine plantations
and bottomland hardwood.� Streams in the
watershed have minimal slopes, low flow, and often become intermittent in the
dry summer season.� Containing first,
second, and third-order streams, this study aims to quantify both spatial and
temporal variations and interactions in streamflow with suspended and dissolved
solids (TSS & TDS) over the entire watershed, including responses to precipitation
events.� Streams have a distinct seasonal
variation, with higher flow and larger storm responses during the winter months,
and low to no-flow with lesser storm responses in the summer season.� Additionally, beaver and debris dams are
prevalent throughout the stream network, resulting in increased storage time
with reductions in peak storm flows and sediment yields. Complicating the
assessment of stream flow and sediment loading in this region, these dams
further decrease the already low slopes and streamflow.� Variation in stream baseflow
is much greater than variations in concentrations of TSS or TDS, and is the major
factor in sediment loading for this area.�
Results from this study can be used to help assess similar streams
systems and improve land management in semi-tropical lowland regions.