Nothing
R/modis_single.R
In agriwater: Evapotranspiration and Energy Fluxes Spatial Analysis
Defines functions
albedo_modis
radiation_modis
evapo_modis
kc_modis
Documented in
albedo_modis
evapo_modis
kc_modis
radiation_modis
#SINGLE VALUES OF AGROMETEOROLOGICAL DATA
#MODIS
#'Crop coefficient (ETa / ET0) using MODIS with single agrometeorological data.
#'
#' @param doy is the Day of Year (DOY)
#' @param RG is the global solar radiation
#' @param Ta is the average air temperature
#' @param a is one of the regression coefficients of SAFER algorithm
#' @param b is one of the regression coefficients of SAFER algorithm
#' @export
#' @import terra
#' @importFrom utils read.csv
#'
#' @return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24"), NDVI, Surface Temperature ("LST"), Crop Coefficient ("kc") and net radiation ("Rn_MJ").
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#' # creating raster which simulate MODIS reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.07, sd = 0.01), 2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"), filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"), filetype = "GTiff", overwrite=TRUE)
#'
# # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater"
#' kc_modis(doy = 134, RG = 17.6, Ta = 27.9, a = 1.8, b = -0.008)
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
kc_modis = function(doy, RG, Ta, a, b){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
NDVI =(b2_mascara-b1_mascara)/(b2_mascara+b1_mascara)
writeRaster(NDVI, "NDVI", filetype = "GTiff", overwrite=TRUE)
lati <- long <- b2_mascara
xy <- crds(b2_mascara)
long[] <- xy[, 1]
long <- crop(long, ext(mask)[1:4])
lati[] <- xy[, 2]
lati <- crop(lati, ext(mask)[1:4])
map1 <- (long/long)*((2*pi)/365)*(doy-1)
Et <- (0.000075+0.001868*cos(map1)-0.032077*sin(map1)-0.014615*cos(2*map1)-0.04089*sin(2*map1))
LAT <- (13+(4*long/60)+(Et/60))
Dec <- 0.006918-0.399912*cos(map1)+0.070257*sin(map1)+0.006758*cos(2*map1)+0.000907*sin(2*map1)-0.002697*cos(3*map1)+0.00148*sin(3*map1)
W <- 15*(LAT-12)*(pi/180)
cos_zwn <- sin(lati*pi/180)*sin(Dec)+cos(lati*pi/180)*cos(Dec)*cos(W)
E0 <- (1.00011+0.034221*cos(map1)+0.00128*sin(map1)+0.000719*cos(2*map1)+0.000077*sin(2*map1))
Ws = acos(((-1)*tan(lati*pi/180))*tan(Dec))
R =(Ws*sin(lati*pi/180)*sin(Dec))+(cos(lati*pi/180)*cos(Dec)*sin(Ws))
RsTOP_aux =(1367/pi)*E0*R
RsTOP = resample(RsTOP_aux, b1_mascara, method="bilinear")
Transm =(RG*11.6)/RsTOP
Rn_coeff =6.99*Ta-39.99
Rn =((1-Alb_24)*(RG*11.6))-(Rn_coeff*Transm)
Rn_MJ =Rn/11.6
writeRaster(Rn_MJ, "Rn_MJ", filetype = "GTiff", overwrite=TRUE)
slope =(4098*(0.6108*exp((17.27*(Ta))/((Ta)+237.3)))/((Ta)+237.3)^2)
LEeq = (slope*Rn)/(slope+0.066)
rm(b1, b2, b1_mascara, b2_mascara, mask, slope, Rn_coeff, RsTOP, RsTOP_aux, R, Ws, E0, cos_zwn, W, Dec, LAT, Et, map1, lati, long)
RR =Alb_24*RG
Emiss_atm = 0.9364*(((-1)*log(Transm))^0.1135)
Emiss_atm[Emiss_atm > 1] <- 1
RLdown_wm2 =(Emiss_atm*5.67*(10^(-8))*((Ta +273.15)^4))
RL_down =RLdown_wm2/11.6
RL_up =(RG-RR+RL_down-Rn_MJ)
Esurf_r1 <- NDVI
Esurf_r1[NDVI < 0] <- 1
Esurf_r1[NDVI >= 0] <- NA
Esurf_r2 <- 1.0035+0.0589*log(NDVI)
Esurf <- merge(Esurf_r1, Esurf_r2)
TS24 =((RL_up*11.6)/((Esurf*5.67)*(10^(-8))))^(0.25)
TS24[TS24 < 273.15] = NA
writeRaster(TS24, "LST", filetype = "GTiff", overwrite=TRUE)
NDVI[NDVI <= 0] = NA
kc=exp((a)+(b*((TS24-273.15)/(Alb_24*NDVI))))
writeRaster(kc, "kc", filetype = "GTiff", overwrite=TRUE)
}
#' Actual evapotranspiration (ETa) using MODIS with single agrometeorological data.
#' @param doy is the Day of Year (DOY)
#' @param RG is the global solar radiation
#' @param Ta is the average air temperature
#' @param ET0 is the reference evapotranspiration
#' @param a is one of the regression coefficients of SAFER algorithm
#' @param b is one of the regression coefficients of SAFER algorithm
#' @export
#' @import terra
#' @importFrom utils read.csv
#'
#' @return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24"), NDVI, Surface Temperature ("LST"), net radiation ("Rn_MJ"), Crop Coefficient ("kc") and Actual Evapotranspiration (evapo).
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#'
#' # creating raster which simulate Sentinel-2 reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"),filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"),filetype = "GTiff", overwrite=TRUE)
#'
# # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater" - it's the same procedure as the used for
#' # evapo_l8(), evapo_l8t(), evapo_modis_grid(), evapo_l8_grid(),
#' # evapo_l8t_grid(), evapo_s2() and evapo_s2_grid()
#' evapo_modis(doy = 134, RG = 17.6, Ta = 27.9, ET0 = 3.8, a = 1.8, b = -0.008)
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
evapo_modis = function(doy, RG, Ta, ET0, a, b){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
NDVI =(b2_mascara-b1_mascara)/(b2_mascara+b1_mascara)
writeRaster(NDVI, "NDVI", filetype = "GTiff", overwrite=TRUE)
lati <- long <- b2_mascara
xy <- crds(b2_mascara)
long[] <- xy[, 1]
long <- crop(long, ext(mask)[1:4])
lati[] <- xy[, 2]
lati <- crop(lati, ext(mask)[1:4])
map1 <- (long/long)*((2*pi)/365)*(doy-1)
Et <- (0.000075+0.001868*cos(map1)-0.032077*sin(map1)-0.014615*cos(2*map1)-0.04089*sin(2*map1))
LAT <- (13+(4*long/60)+(Et/60))
Dec <- 0.006918-0.399912*cos(map1)+0.070257*sin(map1)+0.006758*cos(2*map1)+0.000907*sin(2*map1)-0.002697*cos(3*map1)+0.00148*sin(3*map1)
W <- 15*(LAT-12)*(pi/180)
cos_zwn <- sin(lati*pi/180)*sin(Dec)+cos(lati*pi/180)*cos(Dec)*cos(W)
E0 <- (1.00011+0.034221*cos(map1)+0.00128*sin(map1)+0.000719*cos(2*map1)+0.000077*sin(2*map1))
Ws = acos(((-1)*tan(lati*pi/180))*tan(Dec))
R =(Ws*sin(lati*pi/180)*sin(Dec))+(cos(lati*pi/180)*cos(Dec)*sin(Ws))
RsTOP_aux =(1367/pi)*E0*R
RsTOP = resample(RsTOP_aux, b1_mascara, method="bilinear")
Transm =(RG*11.6)/RsTOP
Rn_coeff =6.99*Ta-39.99
Rn =((1-Alb_24)*(RG*11.6))-(Rn_coeff*Transm)
Rn_MJ =Rn/11.6
writeRaster(Rn_MJ, "Rn_MJ", filetype = "GTiff", overwrite=TRUE)
slope =(4098*(0.6108*exp((17.27*(Ta))/((Ta)+237.3)))/((Ta)+237.3)^2)
LEeq = (slope*Rn)/(slope+0.066)
rm(b1, b2, b1_mascara, b2_mascara, mask, slope, Rn_coeff, RsTOP, RsTOP_aux, R, Ws, E0, cos_zwn, W, Dec, LAT, Et, map1, lati, long)
RR =Alb_24*RG
Emiss_atm = 0.9364*(((-1)*log(Transm))^0.1135)
Emiss_atm[Emiss_atm > 1] <- 1
RLdown_wm2 =(Emiss_atm*5.67*(10^(-8))*((Ta +273.15)^4))
RL_down =RLdown_wm2/11.6
RL_up =(RG-RR+RL_down-Rn_MJ)
Esurf_r1 <- NDVI
Esurf_r1[NDVI < 0] <- 1
Esurf_r1[NDVI >= 0] <- NA
Esurf_r2 <- 1.0035+0.0589*log(NDVI)
Esurf <- merge(Esurf_r1, Esurf_r2)
TS24 =((RL_up*11.6)/((Esurf*5.67)*(10^(-8))))^(0.25)
TS24[TS24 < 273.15] = NA
writeRaster(TS24, "LST", filetype = "GTiff", overwrite=TRUE)
NDVI[NDVI <= 0] = NA
kc=exp((a)+(b*((TS24-273.15)/(Alb_24*NDVI))))
writeRaster(kc, "kc", filetype = "GTiff", overwrite=TRUE)
ET=kc*ET0
writeRaster(ET, "evapo", filetype = "GTiff", overwrite=TRUE)
}
#'Energy balance using Landsat-8 images with single agrometeorological data.
#'@param doy is the Day of Year (DOY)
#'@param RG is the global solar radiation
#'@param Ta is the average air temperature
#'@param ET0 is the reference evapotranspiration
#'@param a is one of the regression coefficients of SAFER algorithm
#'@param b is one of the regression coefficients of SAFER algorithm
#'@export
#' @import terra
#' @importFrom utils read.csv
#'
#'@return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24"), NDVI, Surface Temperature ("LST"), Crop Coefficient ("kc"), Actual Evapotranspiration (evapo), latent heat flux "LE_MJ"), net radiation ("Rn_MJ"), ground heat flux ("G_MJ") and the sensible heat flux ("H_MJ").
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#' # creating raster which simulate Sentinel-2 reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"),filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"),filetype = "GTiff", overwrite=TRUE)
#'
#' # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater" - it's the same procedure as the used for
#' # radiation_l8(), radiation_l8t(), radiation_s2(),
#' # radiation_l8_grid(), radiation_l8t_grid(),
#' # radiation_s2_grid(), radiation_s2() and radiation_modis_grid()
#' radiation_modis(doy = 134, RG = 17.6, Ta = 27.9, ET0 = 3.8, a = 1.8, b = -0.008)
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
radiation_modis = function(doy, RG, Ta, ET0, a, b){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
NDVI =(b2_mascara-b1_mascara)/(b2_mascara+b1_mascara)
writeRaster(NDVI, "NDVI", filetype = "GTiff", overwrite=TRUE)
lati <- long <- b2_mascara
xy <- crds(b2_mascara)
long[] <- xy[, 1]
long <- crop(long, ext(mask)[1:4])
lati[] <- xy[, 2]
lati <- crop(lati, ext(mask)[1:4])
map1 <- (long/long)*((2*pi)/365)*(doy-1)
Et <- (0.000075+0.001868*cos(map1)-0.032077*sin(map1)-0.014615*cos(2*map1)-0.04089*sin(2*map1))
LAT <- (13+(4*long/60)+(Et/60))
Dec <- 0.006918-0.399912*cos(map1)+0.070257*sin(map1)+0.006758*cos(2*map1)+0.000907*sin(2*map1)-0.002697*cos(3*map1)+0.00148*sin(3*map1)
W <- 15*(LAT-12)*(pi/180)
cos_zwn <- sin(lati*pi/180)*sin(Dec)+cos(lati*pi/180)*cos(Dec)*cos(W)
E0 <- (1.00011+0.034221*cos(map1)+0.00128*sin(map1)+0.000719*cos(2*map1)+0.000077*sin(2*map1))
Ws = acos(((-1)*tan(lati*pi/180))*tan(Dec))
R =(Ws*sin(lati*pi/180)*sin(Dec))+(cos(lati*pi/180)*cos(Dec)*sin(Ws))
RsTOP_aux =(1367/pi)*E0*R
RsTOP = resample(RsTOP_aux, b1_mascara, method="bilinear")
Transm =(RG*11.6)/RsTOP
Rn_coeff =6.99*Ta-39.99
Rn =((1-Alb_24)*(RG*11.6))-(Rn_coeff*Transm)
Rn_MJ =Rn/11.6
writeRaster(Rn_MJ, "Rn_MJ", filetype = "GTiff", overwrite=TRUE)
slope =(4098*(0.6108*exp((17.27*(Ta))/((Ta)+237.3)))/((Ta)+237.3)^2)
LEeq = (slope*Rn)/(slope+0.066)
rm(b1, b2, b1_mascara, b2_mascara, mask, slope, Rn_coeff, RsTOP, RsTOP_aux, R, Ws, E0, cos_zwn, W, Dec, LAT, Et, map1, lati, long)
RR =Alb_24*RG
Emiss_atm = 0.9364*(((-1)*log(Transm))^0.1135)
Emiss_atm[Emiss_atm > 1] <- 1
RLdown_wm2 =(Emiss_atm*5.67*(10^(-8))*((Ta +273.15)^4))
RL_down =RLdown_wm2/11.6
RL_up =(RG-RR+RL_down-Rn_MJ)
Esurf_r1 <- NDVI
Esurf_r1[NDVI < 0] <- 1
Esurf_r1[NDVI >= 0] <- NA
Esurf_r2 <- 1.0035+0.0589*log(NDVI)
Esurf <- merge(Esurf_r1, Esurf_r2)
TS24 =((RL_up*11.6)/((Esurf*5.67)*(10^(-8))))^(0.25)
TS24[TS24 < 273.15] = NA
writeRaster(TS24, "LST", filetype = "GTiff", overwrite=TRUE)
NDVI[NDVI <= 0] = NA
kc=exp((a)+(b*((TS24-273.15)/(Alb_24*NDVI))))
ET=kc*ET0
LE_MJ =ET*2.45
writeRaster(LE_MJ, "LE_MJ", filetype = "GTiff", overwrite=TRUE)
G_Rn =3.98*exp(-25.47*Alb_24)
G_MJ =G_Rn*Rn_MJ
writeRaster(G_MJ, "G_MJ", filetype = "GTiff", overwrite=TRUE)
H_MJ =Rn_MJ-LE_MJ-G_MJ
writeRaster(H_MJ, "H_MJ", filetype = "GTiff", overwrite=TRUE)
}
#' Surface Albedo using MODIS images.
#'
#' @export
#' @import terra
#' @importFrom utils read.csv
#'
#' @return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24").
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#' # creating raster which simulate Sentinel-2 reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"),filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.01),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"),filetype = "GTiff", overwrite=TRUE)
#'
#' # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater"
#' albedo_modis()
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
albedo_modis = function(){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
}
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Defines functions albedo_modis radiation_modis evapo_modis kc_modis
Documented in albedo_modis evapo_modis kc_modis radiation_modis
#SINGLE VALUES OF AGROMETEOROLOGICAL DATA
#MODIS
#'Crop coefficient (ETa / ET0) using MODIS with single agrometeorological data.
#'
#' @param doy is the Day of Year (DOY)
#' @param RG is the global solar radiation
#' @param Ta is the average air temperature
#' @param a is one of the regression coefficients of SAFER algorithm
#' @param b is one of the regression coefficients of SAFER algorithm
#' @export
#' @import terra
#' @importFrom utils read.csv
#'
#' @return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24"), NDVI, Surface Temperature ("LST"), Crop Coefficient ("kc") and net radiation ("Rn_MJ").
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#' # creating raster which simulate MODIS reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.07, sd = 0.01), 2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"), filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"), filetype = "GTiff", overwrite=TRUE)
#'
# # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater"
#' kc_modis(doy = 134, RG = 17.6, Ta = 27.9, a = 1.8, b = -0.008)
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
kc_modis = function(doy, RG, Ta, a, b){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
NDVI =(b2_mascara-b1_mascara)/(b2_mascara+b1_mascara)
writeRaster(NDVI, "NDVI", filetype = "GTiff", overwrite=TRUE)
lati <- long <- b2_mascara
xy <- crds(b2_mascara)
long[] <- xy[, 1]
long <- crop(long, ext(mask)[1:4])
lati[] <- xy[, 2]
lati <- crop(lati, ext(mask)[1:4])
map1 <- (long/long)*((2*pi)/365)*(doy-1)
Et <- (0.000075+0.001868*cos(map1)-0.032077*sin(map1)-0.014615*cos(2*map1)-0.04089*sin(2*map1))
LAT <- (13+(4*long/60)+(Et/60))
Dec <- 0.006918-0.399912*cos(map1)+0.070257*sin(map1)+0.006758*cos(2*map1)+0.000907*sin(2*map1)-0.002697*cos(3*map1)+0.00148*sin(3*map1)
W <- 15*(LAT-12)*(pi/180)
cos_zwn <- sin(lati*pi/180)*sin(Dec)+cos(lati*pi/180)*cos(Dec)*cos(W)
E0 <- (1.00011+0.034221*cos(map1)+0.00128*sin(map1)+0.000719*cos(2*map1)+0.000077*sin(2*map1))
Ws = acos(((-1)*tan(lati*pi/180))*tan(Dec))
R =(Ws*sin(lati*pi/180)*sin(Dec))+(cos(lati*pi/180)*cos(Dec)*sin(Ws))
RsTOP_aux =(1367/pi)*E0*R
RsTOP = resample(RsTOP_aux, b1_mascara, method="bilinear")
Transm =(RG*11.6)/RsTOP
Rn_coeff =6.99*Ta-39.99
Rn =((1-Alb_24)*(RG*11.6))-(Rn_coeff*Transm)
Rn_MJ =Rn/11.6
writeRaster(Rn_MJ, "Rn_MJ", filetype = "GTiff", overwrite=TRUE)
slope =(4098*(0.6108*exp((17.27*(Ta))/((Ta)+237.3)))/((Ta)+237.3)^2)
LEeq = (slope*Rn)/(slope+0.066)
rm(b1, b2, b1_mascara, b2_mascara, mask, slope, Rn_coeff, RsTOP, RsTOP_aux, R, Ws, E0, cos_zwn, W, Dec, LAT, Et, map1, lati, long)
RR =Alb_24*RG
Emiss_atm = 0.9364*(((-1)*log(Transm))^0.1135)
Emiss_atm[Emiss_atm > 1] <- 1
RLdown_wm2 =(Emiss_atm*5.67*(10^(-8))*((Ta +273.15)^4))
RL_down =RLdown_wm2/11.6
RL_up =(RG-RR+RL_down-Rn_MJ)
Esurf_r1 <- NDVI
Esurf_r1[NDVI < 0] <- 1
Esurf_r1[NDVI >= 0] <- NA
Esurf_r2 <- 1.0035+0.0589*log(NDVI)
Esurf <- merge(Esurf_r1, Esurf_r2)
TS24 =((RL_up*11.6)/((Esurf*5.67)*(10^(-8))))^(0.25)
TS24[TS24 < 273.15] = NA
writeRaster(TS24, "LST", filetype = "GTiff", overwrite=TRUE)
NDVI[NDVI <= 0] = NA
kc=exp((a)+(b*((TS24-273.15)/(Alb_24*NDVI))))
writeRaster(kc, "kc", filetype = "GTiff", overwrite=TRUE)
}
#' Actual evapotranspiration (ETa) using MODIS with single agrometeorological data.
#' @param doy is the Day of Year (DOY)
#' @param RG is the global solar radiation
#' @param Ta is the average air temperature
#' @param ET0 is the reference evapotranspiration
#' @param a is one of the regression coefficients of SAFER algorithm
#' @param b is one of the regression coefficients of SAFER algorithm
#' @export
#' @import terra
#' @importFrom utils read.csv
#'
#' @return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24"), NDVI, Surface Temperature ("LST"), net radiation ("Rn_MJ"), Crop Coefficient ("kc") and Actual Evapotranspiration (evapo).
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#'
#' # creating raster which simulate Sentinel-2 reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"),filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"),filetype = "GTiff", overwrite=TRUE)
#'
# # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater" - it's the same procedure as the used for
#' # evapo_l8(), evapo_l8t(), evapo_modis_grid(), evapo_l8_grid(),
#' # evapo_l8t_grid(), evapo_s2() and evapo_s2_grid()
#' evapo_modis(doy = 134, RG = 17.6, Ta = 27.9, ET0 = 3.8, a = 1.8, b = -0.008)
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
evapo_modis = function(doy, RG, Ta, ET0, a, b){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
NDVI =(b2_mascara-b1_mascara)/(b2_mascara+b1_mascara)
writeRaster(NDVI, "NDVI", filetype = "GTiff", overwrite=TRUE)
lati <- long <- b2_mascara
xy <- crds(b2_mascara)
long[] <- xy[, 1]
long <- crop(long, ext(mask)[1:4])
lati[] <- xy[, 2]
lati <- crop(lati, ext(mask)[1:4])
map1 <- (long/long)*((2*pi)/365)*(doy-1)
Et <- (0.000075+0.001868*cos(map1)-0.032077*sin(map1)-0.014615*cos(2*map1)-0.04089*sin(2*map1))
LAT <- (13+(4*long/60)+(Et/60))
Dec <- 0.006918-0.399912*cos(map1)+0.070257*sin(map1)+0.006758*cos(2*map1)+0.000907*sin(2*map1)-0.002697*cos(3*map1)+0.00148*sin(3*map1)
W <- 15*(LAT-12)*(pi/180)
cos_zwn <- sin(lati*pi/180)*sin(Dec)+cos(lati*pi/180)*cos(Dec)*cos(W)
E0 <- (1.00011+0.034221*cos(map1)+0.00128*sin(map1)+0.000719*cos(2*map1)+0.000077*sin(2*map1))
Ws = acos(((-1)*tan(lati*pi/180))*tan(Dec))
R =(Ws*sin(lati*pi/180)*sin(Dec))+(cos(lati*pi/180)*cos(Dec)*sin(Ws))
RsTOP_aux =(1367/pi)*E0*R
RsTOP = resample(RsTOP_aux, b1_mascara, method="bilinear")
Transm =(RG*11.6)/RsTOP
Rn_coeff =6.99*Ta-39.99
Rn =((1-Alb_24)*(RG*11.6))-(Rn_coeff*Transm)
Rn_MJ =Rn/11.6
writeRaster(Rn_MJ, "Rn_MJ", filetype = "GTiff", overwrite=TRUE)
slope =(4098*(0.6108*exp((17.27*(Ta))/((Ta)+237.3)))/((Ta)+237.3)^2)
LEeq = (slope*Rn)/(slope+0.066)
rm(b1, b2, b1_mascara, b2_mascara, mask, slope, Rn_coeff, RsTOP, RsTOP_aux, R, Ws, E0, cos_zwn, W, Dec, LAT, Et, map1, lati, long)
RR =Alb_24*RG
Emiss_atm = 0.9364*(((-1)*log(Transm))^0.1135)
Emiss_atm[Emiss_atm > 1] <- 1
RLdown_wm2 =(Emiss_atm*5.67*(10^(-8))*((Ta +273.15)^4))
RL_down =RLdown_wm2/11.6
RL_up =(RG-RR+RL_down-Rn_MJ)
Esurf_r1 <- NDVI
Esurf_r1[NDVI < 0] <- 1
Esurf_r1[NDVI >= 0] <- NA
Esurf_r2 <- 1.0035+0.0589*log(NDVI)
Esurf <- merge(Esurf_r1, Esurf_r2)
TS24 =((RL_up*11.6)/((Esurf*5.67)*(10^(-8))))^(0.25)
TS24[TS24 < 273.15] = NA
writeRaster(TS24, "LST", filetype = "GTiff", overwrite=TRUE)
NDVI[NDVI <= 0] = NA
kc=exp((a)+(b*((TS24-273.15)/(Alb_24*NDVI))))
writeRaster(kc, "kc", filetype = "GTiff", overwrite=TRUE)
ET=kc*ET0
writeRaster(ET, "evapo", filetype = "GTiff", overwrite=TRUE)
}
#'Energy balance using Landsat-8 images with single agrometeorological data.
#'@param doy is the Day of Year (DOY)
#'@param RG is the global solar radiation
#'@param Ta is the average air temperature
#'@param ET0 is the reference evapotranspiration
#'@param a is one of the regression coefficients of SAFER algorithm
#'@param b is one of the regression coefficients of SAFER algorithm
#'@export
#' @import terra
#' @importFrom utils read.csv
#'
#'@return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24"), NDVI, Surface Temperature ("LST"), Crop Coefficient ("kc"), Actual Evapotranspiration (evapo), latent heat flux "LE_MJ"), net radiation ("Rn_MJ"), ground heat flux ("G_MJ") and the sensible heat flux ("H_MJ").
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#' # creating raster which simulate Sentinel-2 reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"),filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"),filetype = "GTiff", overwrite=TRUE)
#'
#' # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater" - it's the same procedure as the used for
#' # radiation_l8(), radiation_l8t(), radiation_s2(),
#' # radiation_l8_grid(), radiation_l8t_grid(),
#' # radiation_s2_grid(), radiation_s2() and radiation_modis_grid()
#' radiation_modis(doy = 134, RG = 17.6, Ta = 27.9, ET0 = 3.8, a = 1.8, b = -0.008)
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
radiation_modis = function(doy, RG, Ta, ET0, a, b){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
NDVI =(b2_mascara-b1_mascara)/(b2_mascara+b1_mascara)
writeRaster(NDVI, "NDVI", filetype = "GTiff", overwrite=TRUE)
lati <- long <- b2_mascara
xy <- crds(b2_mascara)
long[] <- xy[, 1]
long <- crop(long, ext(mask)[1:4])
lati[] <- xy[, 2]
lati <- crop(lati, ext(mask)[1:4])
map1 <- (long/long)*((2*pi)/365)*(doy-1)
Et <- (0.000075+0.001868*cos(map1)-0.032077*sin(map1)-0.014615*cos(2*map1)-0.04089*sin(2*map1))
LAT <- (13+(4*long/60)+(Et/60))
Dec <- 0.006918-0.399912*cos(map1)+0.070257*sin(map1)+0.006758*cos(2*map1)+0.000907*sin(2*map1)-0.002697*cos(3*map1)+0.00148*sin(3*map1)
W <- 15*(LAT-12)*(pi/180)
cos_zwn <- sin(lati*pi/180)*sin(Dec)+cos(lati*pi/180)*cos(Dec)*cos(W)
E0 <- (1.00011+0.034221*cos(map1)+0.00128*sin(map1)+0.000719*cos(2*map1)+0.000077*sin(2*map1))
Ws = acos(((-1)*tan(lati*pi/180))*tan(Dec))
R =(Ws*sin(lati*pi/180)*sin(Dec))+(cos(lati*pi/180)*cos(Dec)*sin(Ws))
RsTOP_aux =(1367/pi)*E0*R
RsTOP = resample(RsTOP_aux, b1_mascara, method="bilinear")
Transm =(RG*11.6)/RsTOP
Rn_coeff =6.99*Ta-39.99
Rn =((1-Alb_24)*(RG*11.6))-(Rn_coeff*Transm)
Rn_MJ =Rn/11.6
writeRaster(Rn_MJ, "Rn_MJ", filetype = "GTiff", overwrite=TRUE)
slope =(4098*(0.6108*exp((17.27*(Ta))/((Ta)+237.3)))/((Ta)+237.3)^2)
LEeq = (slope*Rn)/(slope+0.066)
rm(b1, b2, b1_mascara, b2_mascara, mask, slope, Rn_coeff, RsTOP, RsTOP_aux, R, Ws, E0, cos_zwn, W, Dec, LAT, Et, map1, lati, long)
RR =Alb_24*RG
Emiss_atm = 0.9364*(((-1)*log(Transm))^0.1135)
Emiss_atm[Emiss_atm > 1] <- 1
RLdown_wm2 =(Emiss_atm*5.67*(10^(-8))*((Ta +273.15)^4))
RL_down =RLdown_wm2/11.6
RL_up =(RG-RR+RL_down-Rn_MJ)
Esurf_r1 <- NDVI
Esurf_r1[NDVI < 0] <- 1
Esurf_r1[NDVI >= 0] <- NA
Esurf_r2 <- 1.0035+0.0589*log(NDVI)
Esurf <- merge(Esurf_r1, Esurf_r2)
TS24 =((RL_up*11.6)/((Esurf*5.67)*(10^(-8))))^(0.25)
TS24[TS24 < 273.15] = NA
writeRaster(TS24, "LST", filetype = "GTiff", overwrite=TRUE)
NDVI[NDVI <= 0] = NA
kc=exp((a)+(b*((TS24-273.15)/(Alb_24*NDVI))))
ET=kc*ET0
LE_MJ =ET*2.45
writeRaster(LE_MJ, "LE_MJ", filetype = "GTiff", overwrite=TRUE)
G_Rn =3.98*exp(-25.47*Alb_24)
G_MJ =G_Rn*Rn_MJ
writeRaster(G_MJ, "G_MJ", filetype = "GTiff", overwrite=TRUE)
H_MJ =Rn_MJ-LE_MJ-G_MJ
writeRaster(H_MJ, "H_MJ", filetype = "GTiff", overwrite=TRUE)
}
#' Surface Albedo using MODIS images.
#'
#' @export
#' @import terra
#' @importFrom utils read.csv
#'
#' @return It returns in raster format (.tif) the Surface Albedo at 24h scale ("Alb_24").
#' @examples
#' library(agriwater)
#'
#' # dependencies of package 'agriwater'
#' library(terra)
#'
#' # Using a temporary folder to run example
#' wd <- tempdir()
#' initial = getwd()
#' setwd(wd)
#'
#' # creating raster which simulate Sentinel-2 reflectances - for using
#' # real data, please download:
#' # https://drive.google.com/open?id=14E1wHNLxG7_Dh4I-GqNYakj8YJDgKLzk
#'
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.015),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B2.tif"),filetype = "GTiff", overwrite=TRUE)
#' xy <- matrix(rnorm(4, mean = 0.05, sd = 0.01),2, 2)
#' rast <- rast(xy, crs="+proj=longlat +datum=WGS84")
#' ext(rast) <- c(-40.5,-40.45,-9.5,-9.45)
#' writeRaster(rast, file.path(wd, "B1.tif"),filetype = "GTiff", overwrite=TRUE)
#'
#' # creating mask of study area
#' mask <- as.polygons(rast)
#' writeVector(mask, file.path(getwd(),"mask.shp"), overwrite=TRUE)
#'
#' # using "agriwater"
#' albedo_modis()
#'
#' #Exiting temporary folder and returning to previous workspace
#' setwd(initial)
albedo_modis = function(){
b1 <- rast("B1.tif")
b2 <- rast("B2.tif")
mask <- vect("mask.shp")
b1_crop <- crop(b1, ext(mask)[1:4])
b1_mascara <- mask(b1_crop, mask)
b2_crop <- crop(b2, ext(mask)[1:4])
b2_mascara <- mask(b2_crop, mask)
Alb_inst=b1_mascara*0.41*0.0001+b2_mascara*0.14*0.0001+0.08
Alb_24=1.0223*Alb_inst+ 0.0149
writeRaster(Alb_24, "Alb_24", filetype = "GTiff", overwrite=TRUE)
}
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