stream_power: Calculate stream power for each cross section

In FluvialGeomorph/fluvgeo: A Package for Fluvial Geomorphic Analysis

Calculate stream power for each cross section

Description

Calculates stream power for each cross section in the input xs_dims data frame.

Usage

stream_power(
  xs_dims,
  discharge_method = c("model_measure", "regional_curve", "width_relationship"),
  discharge_value = NULL,
  region = NULL,
  drainage_area = NULL,
  width_method = NULL
)

Arguments

xs_dims	data frame; A data frame of cross section dimensions.
discharge_method	character; The method for calculating discharge (Q). Must be one of: "model_measure", "regional_curve", "width_relationship".
discharge_value	numeric; The discharge value (single value or vector) to use for the stream power calculation. Required if discharge_method = "model_measure".
region	character; The regional curve name used to calculate discharge. Required if discharge_method = "regional_curve". This parameter is passed to the RegionalCurve::RHG function. See the RegionalCurve package for a list of regions with discharge relationships.
drainage_area	numeric; The drainage area (single value or vector) used by the RegionalCurve::RHG function to calculate discharge. Required if discharge_method = "regional_curve".
width_method	character; The name of the width relationship used to calculate discharge (Q) from width. Required if discharge_method = "width_relationship". Must be one of: <list goes here when implemented>

Details

Stream Power Equations Stream power is the rate of energy dissipation against the bed and banks of a river or stream per unit downstream length. It is given by the equation:

\Omega = \rho g Q S

where \Omega is the stream power (kg/m/sec), \rho is the density of water (assumes 1000 kg/m^3), g is acceleration due to gravity (9.8 m/s2), Q is discharge (m^3/s), and S is the channel slope (m/m).

Unit stream power is stream power per unit channel width, and is given by the equation:

\omega = (\rho g Q S) / b

where \omega is the unit stream power, and b is the width of the channel (m).

https://en.wikipedia.org/wiki/Stream_power

Lane's Balance Equation Stream power in the Lane's Balance equation is simply represented by discharge Q and slope S:

\omega = Q S

Determining Discharge The discharge_method parameter specifies the source used for the discharge factor in the stream power equations.

• model_measure Use this option to supply an estimate of discharge from a hydraulic model or field measurement.

• regional_curve Use this option to use an estimate of discharge from a regional curve.

• width_relationship Use this option to use an estimate of discharge from a width relationship

Value

Returns the input xs_dims data frame of cross sections with the calculated stream power variables added.

Examples

# Calculate cross section dimensions
xs_dims <- cross_section_dimensions_L2(xs = fluvgeo::sin_riffle_channel_sf,
                             xs_points = fluvgeo::sin_riffle_channel_points_sf,
                             bankfull_elevation = 103,
                             lead_n = 1,
                             use_smoothing = TRUE,
                             loess_span = 0.5,
                             vert_units = "ft")

# Calculate stream power
xs_dims_sp <- stream_power(xs_dims,
                           discharge_method = "regional_curve",
                           region = "Illinois River",
                           drainage_area = 41)

FluvialGeomorph/fluvgeo documentation built on April 12, 2024, 5:35 p.m.