Encyclopedia of Environmental Science and Engineering, Volume I and II

1080 SEDIMENT TRANSPORT AND EROSION

LIST OF SYMBOLS

a  2 d  reference distance from the stream bed;

A  flow area;

A e  a
D;

b  average channel width;

B  top width of channel;

c  point concentration;

c–  average concentration at a point;

c ′  random component of concentration at a point;

c^  average concentration in the vertical;

C  Chézy coefficient;

C s  Du Boys’ coefficient;

C  constant;

D  flow depth;

(^) D–ij  deformation tensor;
E L^  coefficient of longitudinal dispersion;
E  erosion rate;
f  friction factor;
fcn ()  function of ();
f ()  function of ();
f  silt factor (Lacey);
f b  bed factor (Blench);
f s  side factor (Blench);
F c  generation term:
F t  body force;
g  acceleration due to gravity;
h  coefficient of molecular diffusion;
H  height;
i  index in tensor notation;
i B  portion of material in the bed within a specified
size range;
i B  portion of the bed load in specified size range;
i s  portion of the suspended load in specified size
range;
j  index in tensor notation;
k  constant;
K  constant;
m  porosity;
m  exponent (Simons and Albertson);
M  percent silt-clay;
M o  initial concentration;
n  exponent;
N  time period;
p  exponent;
P  wetted perimeter;
P

•  average pressure;
  P t  turbulence pressure;
  q B  bed load
  unit width;
  q s  suspended load
  unit width;
  q TB  total bed material load
  unit width;
  q T  total sediment load
  unit width;
  q w  wash load
  unit width;
  Q s  total suspended load;
  Q T  total sediment load;
  Q  water discharge;
  R  hydraulic radius;
  R ′  hydraulic radius associated with grain roughness;

R ′′  hydraulic radius associated with bed form;

r  ( S s –1);

S s  specific weight of sediment grains;

S o  bed slope;

S e  energy slope;

SY  average annual sediment yield;

t  time;

T  time period;

u i  random component of the velocity U;

U i  instantaneous velocity in direction i;

U

• i^  average velocity in direction i;^
  U *  friction velocity;
  U


• 
  

  x^  average point velocity in the x -direction;
  U x  average velocity in the vertical;
  v  stream velocity;
  v S  terminal settling velocity of sediment particles;
  w  wash load;
  W  channel width;
  x  coordinate;
  y  coordinate;
  z  coordinate;
  Z 

  
  

(^)
n
bk
s
U
;
b  (^) m

c ;
g  specific weight of water;
gs  specific weight of sediment grains;
g  bulk dry specific weight of a deposit;
d  laminar sub-layer thickness;
d ij  Kronecker delta;
(^) m  kinematic eddy viscosity;
(^) c  kinematic eddy transport coefficient;
k  von Karman constant; 0.4;
  wave length;
μ  dynamic viscosity;
v  kinematic viscosity;
r  density;
s ji  stress tensor;
t o  bed shear stress;
t c  critical shear stress;
  sediment transport function;
c  flow intensity function.
REFERENCES

1. Brown, C.B., Sediment Transportation, Chapter XII, Engineering
   Hydraulics, H. Rouse, Editor, J. Wiley and Sons, New York, 1950.


2. Turner, D.J., Dams and ecology, Civil Engineering, ASCE, Sept. 1971,
   pp. 76–80.


3. Leopold, L.B., M.G. Wolman, and J.P. Miller, Fluvial Processes in
   Geomorphology, W.H. Freeman and Co., San Francisco, 1964.


4. Einstein, H.A., Formulas for the transportation of bed load, Trans.
   ASCE, 107, 1942.


5. Einstein, H.A., The bed-load function for sediment transportation in
   open channel flows, US Dept. of Agriculture Technical Bulletin No.
   1026, 1950.


6. Bishop, A.A., D.B. Simons, and E.V. Richardson, Total bedmaterial
   transport, Proc. ASCE, 91, HY2, March 1965, pp. 175–191.


7. Chow, and Ven Te, Open-Channel Hydraulics, McGraw-Hill Co.,
   New York, 1959.


8. Chow, and Ven Te, Handbook of Applied Hydrology, McGraw-Hill Co.,
   New York, 1964.

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