n_jarrett1984 {HYDROCAL}

Compute grain roughness via Jarrett (1984)

Description

n_jarrett1984 calculate Manning's n using the Jarrett (1984) Method for estimating grain roughness

Usage

n_jarrett1984(radius, slope, restrict = TRUE)

Arguments

radius

hydraulic radius (R) in meters. The original model was calibrated for 0.15 m < R < 1.68 m

slope

channel slope (S) in m/m. The original model was calibrated for 0.002 < S < 0.04.

restrict

allows for function parameters to restrict certain values. Type bool. Default TRUE.

Value

Manning's n

References

Jarrett, R. D. 1984. Hydraulics of High-Gradient Streams. Journal of Hydraulic Engineering. American Society of Civil Engineers, Vol. 110 (11), pp. 1519-1539.

Examples

# Result: Manning's n of 0.102
n_jarrett1984(0.3,0.03)

# Result: Manning's n of 0.065
n_jarrett1984(1,0.015)

# Result: Slope must be within 0.002 and 0.04 m.
n_jarrett1984(12,0.05)