WindChill

Zusammenfassung

Identifies dangerous winter conditions that, depending on exposure times to the elements, can result in frostbite or hypothermia.

Diskussion

The formula the function uses to compute wind chill is as follows:

Wind Chill = 35.74 + (0.6215 * T) - (35.75 * WS^0.16) + (0.4275 * T * WS^0.16)

• T = Air Temperature in degrees Fahrenheit
• WS = Wind speed in miles per hour

For more information about how this function works, see the Wind Chill raster function.

The referenced raster dataset for the raster object is temporary. To make it permanent, you can call the raster object's save method.

Syntax

WindChill (temperature_raster, wind_speed_raster, {temperature_units}, {wind_speed_units}, {wind_chill_units})

Parameter	Erläuterung	Datentyp
temperature_raster [temperature_raster,...]	Ein Einzelband-Raster, in dem Pixelwerte die Umgebungslufttemperatur darstellen.	Raster
wind_speed_raster [wind_speed_raster,...]	A single-band raster where pixel values represent wind speed.	Raster
temperature_units	Die mit dem Eingabe-Temperatur-Raster verknüpfte Maßeinheit. Die verfügbaren Eingabeeinheiten lauten Celsius, Fahrenheit und Kelvin. (Der Standardwert ist Fahrenheit)	String
wind_speed_units	Defines the unit of measurement for the wind-speed raster: mph—Miles per hour km/h—Kilometers per hour m/s—Meters per second ft/s—Feet per second kn—Knots (Der Standardwert ist mph)	String
wind_chill_units	Die mit dem Ausgabe-Raster verknüpfte Maßeinheit. Die verfügbaren Ausgabeeinheiten lauten Celsius, Fahrenheit und Kelvin. (Der Standardwert ist Fahrenheit)	String

Rückgabewert

Datentyp	Erläuterung
Raster	The output raster.

Codebeispiel

WindChill example 1

Calculates wind chill based on the temperature and wind speed from the input raster.

from arcpy.ia import *
out_windchill_raster = WindChill("temperature.tif", "windspeed.tif", "",
                                 "km/h", "Celsius")
out_windchill_raster.save("C:/arcpyExamples/outputs/wind_chill_C.tif")

WindChill example 2

Calculates wind chill based on the temperature and wind speed from the input raster.

# Import system modules
import arcpy
from arcpy.ia import *

# Set the analysis environments
arcpy.env.workspace = "C:/arcpyExamples/data"

# Set the local variables
in_temperature_raster = "temperature.tif"
in_wind_speed_raster  = "windspeed.tif"

# Execute WindChill function
out_windchill_raster = WindChill(in_temperature_raster, in_wind_speed_raster,
                                 "", "knots", "Kelvin")
# Save the output
out_windchill_raster.save("C:/arcpyExamples/outputs/wind_chill_K.tif")