SAGA-GIS Tool Library Documentation (v9.1.2)

Tool Lapse Rate Based Temperature Downscaling

The Lapse Rate Based Temperature Downscaling is quite simple, but might perform well for mountainous regions, where the altitudinal gradient is the main driver for local temperature variation. First, a given lapse rate is used to estimate sea level temperatures from elevation and temperature data at a coarse resolution. Second, the same lapse rate is used to estimate the terrain surface temperature using higher resoluted elevation data and the spline interpolated sea level temperatures from the previous step. The lapse rates can be defined as one constant value valid for the whole area of interest, or as varying value as defined by an additional input grid. Alternatively a constant lapse rate can be estimated from the coarse resolution input with a regression analysis.

Parameters

 NameTypeIdentifierDescriptionConstraints
InputElevationGrid, inputLORES_DEM--
TemperatureGrid, inputLORES_T--
Lapse RateGrid, inputLORES_LAPSE--
ElevationGrid, inputHIRES_DEM--
OutputSea Level Temperature (*)Grid, output, optionalLORES_SLT--
TemperatureGrid, outputHIRES_T--
Regression Summary (*)Table, output, optionalREGRS_SUMMARY--
OptionsCoarse ResolutionGrid systemLORES_GRID_SYSTEM--
High ResolutionGrid systemHIRES_GRID_SYSTEM--
Lapse RateChoiceLAPSE_METHOD-Available Choices:
[0] constant lapse rate
[1] constant lapse rate from regression
[2] varying lapse rate from grid
Default: 1
RegressionChoiceREGRS_LAPSE-Available Choices:
[0] elevation
[1] elevation and position
[2] elevation and position (2nd order polynom)
Default: 2
Limit Minimum Lapse RateBooleanLIMIT_LAPSEIf set, lapse rates from regression are limited to a minimum as specified by the constant lapse rate parameter.Default: 0
Constant Lapse RateFloating pointCONST_LAPSEConstant lapse rate in degree of temperature per 100 meter.Default: 0.600000
(*) optional

Command-line

Usage: saga_cmd climate_tools 30 [-LORES_DEM <str>] [-LORES_T <str>] [-LORES_LAPSE <str>] [-LORES_SLT <str>] [-HIRES_DEM <str>] [-HIRES_T <str>] [-LAPSE_METHOD <str>] [-REGRS_SUMMARY <str>] [-REGRS_LAPSE <str>] [-LIMIT_LAPSE <str>] [-CONST_LAPSE <double>]
  -LORES_DEM:<str>     	Elevation
	Grid, input
  -LORES_T:<str>       	Temperature
	Grid, input
  -LORES_LAPSE:<str>   	Lapse Rate
	Grid, input
  -LORES_SLT:<str>     	Sea Level Temperature
	Grid, output, optional
  -HIRES_DEM:<str>     	Elevation
	Grid, input
  -HIRES_T:<str>       	Temperature
	Grid, output
  -LAPSE_METHOD:<str>  	Lapse Rate
	Choice
	Available Choices:
	[0] constant lapse rate
	[1] constant lapse rate from regression
	[2] varying lapse rate from grid
	Default: 1
  -REGRS_SUMMARY:<str> 	Regression Summary
	Table, output, optional
  -REGRS_LAPSE:<str>   	Regression
	Choice
	Available Choices:
	[0] elevation
	[1] elevation and position
	[2] elevation and position (2nd order polynom)
	Default: 2
  -LIMIT_LAPSE:<str>   	Limit Minimum Lapse Rate
	Boolean
	Default: 0
  -CONST_LAPSE:<double>	Constant Lapse Rate
	Floating point
	Default: 0.600000