Note, the symbols don’t translate with some browers… I am working on the problem.  Use Internet Explorer for now.

 

Table of equations, mainly for rivers.

 

Basic

 

 

Force balance

SF = 0, or  SF = ma

The second form is used if there are any accelerations

Hydro or litho static pressure

P = r g d

r is the material density, and d is the depth of burial

Shear and normal stress in a fluid

 

 

Shear stress, parallel to slope at some depth (depth perpendicular to slope, but often just the vertical depth is used.)

t = rgd sina

See notes on slope angles and depths

Normal stress, perpendicular to slope

s = rgd cosa

 

Reynolds number

Re = r v d / m

Where v is a flow direction velocity and d is a cross stream dimension

Froude number

Fr  = v / ( g d )1/2

 

Stoke’s setting velocity

w =  (rs - rf) g D2 / ( 18 m )

 

Shear velocity

U* = ( tb / rf)1/2

 

Bernoulli pressure/velocity

DPw = - (Dv)2 /2

 

Shield’s parameter

Q = tb / (rs - rf) g D

This equation can be inverted to get the critical shear stress tc  to get a particle moving

Mannings equation

V = R2/3 S1/2  / n

R is the cross-section area divided by the wetted perimeter, S is slope and n is tabulated, this equation is written for MKS units only

Chezy eqn.

V = C R1/2 S1/2 

 

MPM equation for sediment load

qs = A (tb - tc) 3/2

Bedload or total load per unit width of channel

Super-elevation in meander bends

Dz = v2 w / (gR)

W is the channel width, and R is the bend radius

Alluvial diffusion equation

If  the second term is ignored, this is just the simple diffusion equation, and can be thought of in terms of behavior just like the rainsplash equation

Bedrock kinematic equation

This is a kinematic wave equation with velocity Eqw.