HeatIndex

概要

Calculates apparent temperature based on ambient temperature and relative humidity. The apparent temperature is often described as how hot it feels to the human body.

ディスカッション

The formula that the Heat Index function uses to compute heat index is as follows:

Heat Index = ( -42.379 + (2.04901523 * T) + (10.14333127 * R) 
              - (0.22475541 * TR) - (6.83783e-3 * TT) - (5.481717e-2 * RR) 
              + (1.22874e-3 * TTR) + (8.5282e-4 * TRR) - (1.99e-6 * TTRR) )

where:

• T = Air temperature
• R = Relative humidity

For more information about how this function works, see the Heat Index 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.

構文

HeatIndex (temperature_raster, relative_humidity_raster, {temperature_unit}, {heat_index_unit})

パラメーター	説明	データ タイプ
temperature_raster	ピクセル値で周辺気温を表すシングルバンド ラスター。	Raster
relative_humidity_raster	A single-band raster where pixel values represent relative humidity as a percentage value between 0 and 100.	Raster
temperature_unit	入力される温度ラスターに関連付けられる測定単位。使用できる入力単位は、摂氏度、華氏度、ケルビン度です。 (デフォルト値は次のとおりです Fahrenheit)	String
heat_index_unit	出力ラスターに関連付けられる測定単位。使用できる出力単位は、摂氏度、華氏度、ケルビン度です。 (デフォルト値は次のとおりです Fahrenheit)	String

戻り値

データ タイプ	説明
Raster	The output raster.

コードのサンプル

HeatIndex example 1

This example calculates the heat index based on ambient temperature and relative humidity from the input raster.

from arcpy.ia import *
out_heatindex_raster = HeatIndex("temperature", "relative_humidity", "Celsius", "Kelvin")
out_heatindex_raster.save("C:/arcpyExamples/outputs/heat_index_K.tif")

HeatIndex example 2

This example calculates the heat index based on ambient temperature and relative humidity 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_relative_humidity_raster  = "relativehumid.tif"

# Execute the HeatIndex function
out_heat_index_raster = HeatIndex(in_temperature_raster, in_relative_humidity_raster, "", "Celsius")

# Save the output
out_heat_index_raster.save("C:/arcpyExamples/outputs/heat_index_C.tif")