Isochrones Variable Speed

Author: V.Olaya (c) 2004, V.Wichmann (c) 2015
Menu: Terrain Analysis | Hydrology | Dynamics

Description

Calculation of isochrones with variable speed. In case a cell in an optional input grid is NoData, the corresponding parameter value will be used instead of skipping this cell. This is the non-interactive tool version, where the target point can be specified either as point shapefile (the first point in the file will be used) or by target coordinates.

References

Al-Smadi, Mohammad (1998): Incorporating spatial and temporal variation of watershed response in a gis-based hydrologic model. Faculty of the Virginia Polythecnic Insitute and State University. MsC Thesis. online.
Mart__nez __lvarez, V.; Dal-R__ Tenreiro, R.; Garc__a Garc__a, A. I.; Ayuga T__llez, F. (): Modelaci__n distribuida de la escorrent__a superficial en peque__as cuencas mediante SIG. Evaluaci__n experimental.
Olaya, V. (2004): Hidrologia computacional y modelos digitales del terreno. Alqua. 536 pp.

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Elevation	grid, input	`DEM`	-	-
	Slope	grid, input	`SLOPE`	-	-
	Catchment Area	grid, input	`FLOWACC`	-	-
	Curve Number	grid, input, optional	`CN`	-	-
	Manning's N	grid, input, optional	`MANNING`	-	-
	Target Point	shapes, input, optional	`TARGET_PT`	A point shapefile with the target point.	-
Output	Time Out(h)	grid, output	`TIME`	-	-
Output	Speed (m/s)	grid, output	`SPEED`	-	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Avg. Manning's N	floating point number	`AVGMANNING`	-	Default: 0.150000
	Avg. Curve Number	floating point number	`AVGCN`	-	Default: 75.000000
	Mixed Flow Threshold (ha)	floating point number	`THRSMIXED`	-	Default: 18.000000
	Channel Definition Threshold (ha)	floating point number	`THRSCHANNEL`	-	Default: 360.000000
	Avg. Rainfall Intensity (mm/h)	floating point number	`AVGRAINFALL`	-	Default: 1.000000
	Channel side slope(m/m)	floating point number	`CHANSLOPE`	-	Default: 0.500000
	Min. Flow Speed (m/s)	floating point number	`MINSPEED`	-	Default: 0.050000
	Target X Coordinate	floating point number	`TARGET_PT_X`	The x-coordinate of the target point in world coordinates [map units]	Default: 0.000000
	Target Y Coordinate	floating point number	`TARGET_PT_Y`	The y-coordinate of the target point in world coordinates [map units]	Default: 0.000000

Command Line


Usage: saga_cmd ta_hydrology 30 [-DEM ] [-SLOPE ] [-FLOWACC ] [-CN ] [-MANNING ] [-TIME ] [-SPEED ] [-AVGMANNING ] [-AVGCN ] [-THRSMIXED ] [-THRSCHANNEL ] [-AVGRAINFALL ] [-CHANSLOPE ] [-MINSPEED ] [-TARGET_PT_X ] [-TARGET_PT_Y ] [-TARGET_PT ]
  -DEM:           	Elevation
	grid, input
  -SLOPE:         	Slope
	grid, input
  -FLOWACC:       	Catchment Area
	grid, input
  -CN:            	Curve Number
	grid, input, optional
  -MANNING:       	Manning's N
	grid, input, optional
  -TIME:          	Time Out(h)
	grid, output
  -SPEED:         	Speed (m/s)
	grid, output
  -AVGMANNING: 	Avg. Manning's N
	floating point number
	Default: 0.150000
  -AVGCN:      	Avg. Curve Number
	floating point number
	Default: 75.000000
  -THRSMIXED:  	Mixed Flow Threshold (ha)
	floating point number
	Default: 18.000000
  -THRSCHANNEL:	Channel Definition Threshold (ha)
	floating point number
	Default: 360.000000
  -AVGRAINFALL:	Avg. Rainfall Intensity (mm/h)
	floating point number
	Default: 1.000000
  -CHANSLOPE:  	Channel side slope(m/m)
	floating point number
	Default: 0.500000
  -MINSPEED:   	Min. Flow Speed (m/s)
	floating point number
	Default: 0.050000
  -TARGET_PT_X:	Target X Coordinate
	floating point number
	Default: 0.000000
  -TARGET_PT_Y:	Target Y Coordinate
	floating point number
	Default: 0.000000
  -TARGET_PT:     	Target Point
	shapes, input, optional