chelsa and worldclim temperature comparison

import library

library(raster)

## Loading required package: sp

library(ggExtra)
library(spatialEco)

## spatialEco 0.1-5

## Type se.news() to see new features/changes/bug fixes.

Read tif File

worldclim<-raster("worldclim_tw.tif")
chelsa<- raster("Chelsa_tw.tif")

worldclim   ## worldclim information

## class       : RasterLayer 
## dimensions  : 517, 769, 397573  (nrow, ncol, ncell)
## resolution  : 0.008337745, 0.008331238  (x, y)
## extent      : 117.8741, 124.2859, 21.47609, 25.78334  (xmin, xmax, ymin, ymax)
## coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 
## data source : F:\R_project\worldclim_chelsa_climate_compare\worldclim_tw.tif 
## names       : worldclim_tw 
## values      : -4.4, 15.8  (min, max)

chelsa   ## worldclim information

## class       : RasterLayer 
## dimensions  : 517, 769, 397573  (nrow, ncol, ncell)
## resolution  : 0.008337745, 0.008331238  (x, y)
## extent      : 117.8741, 124.2859, 21.47609, 25.78334  (xmin, xmax, ymin, ymax)
## coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 
## data source : F:\R_project\worldclim_chelsa_climate_compare\Chelsa_tw.tif 
## names       : Chelsa_tw 
## values      : -4.721886, 13.61559  (min, max)

temperation condition of Taiwan

par(mfrow=c(1,2))
plot(chelsa,main="chelsa Jan tmin")
plot(worldclim,main="worldclim Jan tmin")

difference of temperation condition of Taiwan

difference<- overlay(chelsa,
                      worldclim,
                        fun=function(chelsa,worldclim){return(chelsa-worldclim)})


plot(difference,main="chelsa - worldclim Tmin")

histogram of temperation condition of Taiwan

layout(matrix(c(1,1,2,3), 2, 2, byrow = TRUE))

hist(difference, 
     col="springgreen4",
     main="Histogram of the difference Tmin between chelsa & worldclim",
     ylab="Number of Pixels",
     xlab="Temperature")
hist(worldclim,main="Histogram of worldclim January Tmin",xlab="Temperature",ylab="Number of Pixels")

## Warning in sampleInt(length(x), size): size changed to n because it cannot
## be larger than n when replace is FALSE

## Warning in .hist1(x, maxpixels = maxpixels, main = main, plot = plot, ...):
## 25% of the raster cells were used (of which 54% were NA). 45944 values
## used.

hist(chelsa,main="Histogram of chelsa January Tmin",xlab="Temperature",ylab="Number of Pixels")

## Warning in sampleInt(length(x), size): size changed to n because it cannot
## be larger than n when replace is FALSE

## Warning in .hist1(x, maxpixels = maxpixels, main = main, plot = plot, ...):
## 25% of the raster cells were used (of which 54% were NA). 46120 values
## used.

correlation of temperation condition of Taiwan

r.cor<-rasterCorrelation(worldclim,chelsa,s = 5, type = "pearson")
plot(r.cor)

worldclim<-raster("worldclim_v9.tif")
chelsa<- raster("Chelsa_v5.tif")

worldclim   ## worldclim information

## class       : RasterLayer 
## dimensions  : 1167, 1407, 1641969  (nrow, ncol, ncell)
## resolution  : 0.008332632, 0.008334438  (x, y)
## extent      : 96.86063, 108.5846, 25.26633, 34.99262  (xmin, xmax, ymin, ymax)
## coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 
## data source : F:\R_project\worldclim_chelsa_climate_compare\worldclim_v9.tif 
## names       : worldclim_v9

chelsa   ## worldclim information

## class       : RasterLayer 
## dimensions  : 1167, 1407, 1641969  (nrow, ncol, ncell)
## resolution  : 0.008332632, 0.008334438  (x, y)
## extent      : 96.86063, 108.5846, 25.26633, 34.99262  (xmin, xmax, ymin, ymax)
## coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 
## data source : F:\R_project\worldclim_chelsa_climate_compare\Chelsa_v5.tif 
## names       : Chelsa_v5

temperation condition of Sichuan

par(mfrow=c(1,2))
plot(chelsa,main="chelsa Jan tmin")
plot(worldclim,main="worldclim Jan tmin")

difference of temperation condition of Sichuan

difference<- overlay(chelsa,
                      worldclim,
                        fun=function(chelsa,worldclim){return(chelsa-worldclim)})


plot(difference,main="chelsa - worldclim Tmin")

histogram of temperation condition of Sichuan

layout(matrix(c(1,1,2,3), 2, 2, byrow = TRUE))

hist(difference, 
     col="springgreen4",
     main="Histogram of the difference Tmin between chelsa & worldclim",
     ylab="Number of Pixels",
     xlab="Temperature")
hist(worldclim,main="Histogram of worldclim January Tmin",xlab="Temperature",ylab="Number of Pixels")

## Warning in .hist1(x, maxpixels = maxpixels, main = main, plot = plot, ...):
## 6% of the raster cells were used. 100000 values used.

hist(chelsa,main="Histogram of chelsa January Tmin",xlab="Temperature",ylab="Number of Pixels")

## Warning in .hist1(x, maxpixels = maxpixels, main = main, plot = plot, ...):
## 6% of the raster cells were used. 100000 values used.

correlation of temperation condition of Sichuan

r.cor<-rasterCorrelation(worldclim,chelsa,s = 5, type = "pearson")
plot(r.cor)