Sediment Transport Calculator

Calculate bedload transport rate, shear stress, and transport mode from stream velocity, grain size, water depth, and slope.

Stream Velocity (m/s)

Grain Size D (mm)

Water Depth (m)

Channel Slope

Tab to move between fields

Bedload Transport Rate

0.01 kg/m/s

Sediment Moving?

Yes

Transport Mode

Bedload only

Bed Shear Stress49.05 Pa

Critical Shear Stress1.522 Pa

Shields Parameter1.5152

Froude Number0.479

Stream Power73.575 W/m²

Rouse Number3.62

How to Use This Calculator

Enter Stream Velocity in m/s, Grain Size D in mm, and Water Depth in m.
Enter Channel Slope as a dimensionless ratio (rise/run).
Review whether Sediment is Moving based on comparison of bed shear stress to critical shear stress.
Check Transport Mode (bedload, mixed load, or suspended load) and Bedload Transport Rate in kg/m/s.
Use Froude Number and Rouse Number to characterize flow regime and sediment suspension.

How the result changes with Water Depth (m)

Water Depth (m)	Bedload Transport Rate	Sediment Moving?	Transport Mode
10	0.17 kg/m/s	Yes	Mostly suspended
35	1.11 kg/m/s	Yes	Wash load (fully suspended)
65	2.81 kg/m/s	Yes	Wash load (fully suspended)
90	4.58 kg/m/s	Yes	Wash load (fully suspended)

Stream Velocity (m/s): Average stream flow velocity in meters per second.
Grain Size D (mm): Median grain diameter in mm. Sand: 0.06–2, Gravel: 2–64, Cobble: 64–256.
Water Depth (m): Average water depth in meters.
Channel Slope: Dimensionless channel bed slope (rise/run). Typical rivers: 0.0001–0.05.

qb = 8(τ* − τ*c)^1.5 × √[(ρs/ρ − 1)gD³] (Meyer-Peter & Müller)

Identify Input Parameters
4 parameters
Stream Velocity (m/s) = 1.5, Grain Size D (mm) = 2, Water Depth (m) = 1, Channel Slope = 0.005 = 4 input(s) provided
Calculate Bedload Transport Rate
Bedload Transport Rate = Number(bedload.toExponential(3))
0.005121 = 0.005121
Calculate Sediment Moving?
Yes = Yes
Calculate Transport Mode
Transport Mode
Bedload only = Bedload only
Calculate Bed Shear Stress
Bed Shear Stress
49.05 = 49.05
Calculate Critical Shear Stress
Critical Shear Stress
1.522 = 1.522