SAGA 9.4.2 | Tool Library Documentation

Wind Effect (Windward / Leeward Index)


Description

The 'Wind Effect' is a dimensionless index. Values below 1 indicate wind shadowed areas whereas values above 1 indicate areas exposed to wind, all with regard to the specified wind direction. Wind direction, i.e. the direction into which the wind blows, might be either constant or variying in space, if a wind direction grid is supplied.


References


Parameters

 NameTypeIdentifierDescriptionConstraints
InputElevationgrid, inputDEM--
Wind Directiongrid, input, optionalDIRDirection into which the wind blows, starting with 0 for North and increasing clockwise.-
Wind Speedgrid, input, optionalLEN--
OutputWind Effectgrid, outputEFFECT--
Effective Air Flow Heightsgrid, output, optionalAFH--
OptionsGrid Systemgrid systemPARAMETERS_GRID_SYSTEM--
Wind Direction UnitschoiceDIR_UNITS-Available Choices: [0] radians [1] degree Default: 0
Scalingfloating point numberLEN_SCALE-Default: 1.000000
Search Distance [km]floating point numberMAXDIST-Minimum: 0.000000 Default: 300.000000
Constant Wind Directionfloating point numberDIR_CONSTconstant direction into the wind blows, given as degreeDefault: 135.000000
Old VersionbooleanOLDVERuse old version for constant wind direction (no acceleration and averaging option)Default: 0
Accelerationfloating point numberACCEL-Minimum: 1.000000 Default: 1.500000
Elevation AveragingbooleanPYRAMIDSuse more averaged elevations when looking at increasing distancesDefault: 0

Command Line


Usage: saga_cmd ta_morphometry 15 [-DEM ] [-DIR ] [-DIR_UNITS ] [-LEN ] [-LEN_SCALE ] [-EFFECT ] [-AFH ] [-MAXDIST ] [-DIR_CONST ] [-OLDVER ] [-ACCEL ] [-PYRAMIDS ]
  -DEM:         	Elevation
	grid, input
  -DIR:         	Wind Direction
	grid, input, optional
  -DIR_UNITS:   	Wind Direction Units
	choice
	Available Choices:
	[0] radians
	[1] degree
	Default: 0
  -LEN:         	Wind Speed
	grid, input, optional
  -LEN_SCALE:	Scaling
	floating point number
	Default: 1.000000
  -EFFECT:      	Wind Effect
	grid, output
  -AFH:         	Effective Air Flow Heights
	grid, output, optional
  -MAXDIST:  	Search Distance [km]
	floating point number
	Minimum: 0.000000
	Default: 300.000000
  -DIR_CONST:	Constant Wind Direction
	floating point number
	Default: 135.000000
  -OLDVER:      	Old Version
	boolean
	Default: 0
  -ACCEL:    	Acceleration
	floating point number
	Minimum: 1.000000
	Default: 1.500000
  -PYRAMIDS:    	Elevation Averaging
	boolean
	Default: 0