Selected Water Quality Processes in Rivers and Streams - Hydro-Environmental Analysis: Freshwater Environments - page 141

TABLE 5.1
Comparison of Relative Contributions of Bank Erosion

Dominant Bed
Material

Contribution
from Banks (%) Stream Ecoregion

James Creek, MS Southeastern Plains Sand/clay 78

Shades Creek, AL Ridge and Valley Gravel 71-82

Goodwin Creek, MS Mississippi Valley Loess Plains Sand/gravel 64

Yalobusha River, MS Southeastern Plains Clay/sand 90 a

Obion-Forked Deer River, TN Mississippi Valley Loess Plains Sand 81 a

Source: Simon, A., Adjustment processes in luvial systems implications for streambank instability and control, National
Sedimentation Laboratory, Oxford, MS, from a workshop presented at the EWRI Water Resource Congress
2009, Kansas City, MO, 2009.
a Represents the contribution from banks relative to all channel sources.

TABLE 5.2
Sediment Size Categories

Category Dia. (mm) Wentworth Scale

Boulder >256 <−8

Cobble
Large

128-256 −7

Small 64-128

−6

Pebble
Large

32-64 −5

Small 16-32

−4

Gravel
Coarse

8-16 −3

Medium 4-8

−2

Small 2-4 −1

Sand
Very coarse

1-2 0

Coarse 0.5-1 1

Medium 0.25-0.5 2

Fine 0.125-0.25 3

Very ine 0.063-0.125 4

Silt <0.063 >5

Source: Water on the Web, Monitoring Minnesota Lakes on the Internet and training
water science technicians for the future—A national on-line curriculum using
advanced technologies and real-time data, University of Minnesota, Duluth,
MN, 2004. Available at http://WaterOntheWeb.org.

The goal of many river management and restoration projects is to reduce sediment load-
ings and the adverse impacts of sediments. This is commonly done by the implementation of
best management practices (BMPs). Guidance on sediment BMPs is available from a variety
of agencies and organizations, including the Natural Resources Conservation Service (NRCS),
the USDA Forest Service (USFS), the Bureau of Land Management (BLM), state transportation