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For this work Data are obtained from:- For Raster:-https://download.hermes.com.np/land-cover-map-of-nepal-2010/. For Vector :-https://cellapp.co/download-nepals-new-map-vector-image/. Rupandehi District was then selected and exported as a part of this work (named here as RupandehiLocalPlace).

Then, I clipped a raster file based on vector shapefile. The code I used as shown:-

library(sf)
library(rgdal)
library(raster)
setwd("C:/Users/lenovo/Desktop/EM")
LCN<-raster("np_lc_2010_v2f.tif")
RLU<-shapefile("RupandehiLocalPlace")
proj4string(RLU)
proj4string(LCN)
plot(LCN)
plot(RLU)
proj4string(LCN)<-CRS("+proj=utm +zone=44 +datum=WGS84 +units=m 
+no_defs")
raster::projection(LCN)
LCN<-crop(LCN,RLU)
plot(LCN,main="Forest Area in 2019")
plot(LCN,
main="Forest Area in 2019",
axes=TRUE)
plot(RLU,add= TRUE)

The result obtained is shown below:- enter image description here

But, I don't have an idea of masking data. Could someone let me know how to mask these data (raster based on vector). Also, I couldn't see spatial scale in either of direction. How can this be solved? I would be thankful for your answers.

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5
  • How are you reprojecting the file?
    – aldo_tapia
    Jun 11, 2022 at 17:33
  • @aldo_tapia-I tried cropping raster with vector and don't have an idea of masking. I have edited my questions little bit. Please have a look. Hope for your constructive answers. Thank you.
    – Walker
    Jun 11, 2022 at 19:59
  • I recommend you to upload sample files to see what's happening
    – aldo_tapia
    Jun 12, 2022 at 0:07
  • BTW, check ?raster::mask and read the documentation. Since that could be a slow process, change the functions to terra package which is an improved (faster) raster package
    – aldo_tapia
    Jun 12, 2022 at 0:18
  • @aldo_tapia, For this work Data are obtained from:- For Raster:-download.hermes.com.np/land-cover-map-of-nepal-2010. For Vector :-cellapp.co/download-nepals-new-map-vector-image. Rupandehi District was then selected and exported as a part of this work (named here as RupandehiLocalPlace).
    – Walker
    Jun 12, 2022 at 0:28

1 Answer 1

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First mask, then crop. This is using terra package (although I think you shared the wrong raster). Also you can select the district and reproject easily:

library(terra)

r <- rast('~/Downloads/Land%20Cover%20Map%20of%20Nepal%202010/np_lc_2010_v2f.tif')
v <- vect('~/Downloads/Local Unit/local_unit.shp')

v <- v[v$DISTRICT == "RUPANDEHI",]

v <- project(v,r)

plot(mask(crop(r,v),v))
plot(v, add = T)

enter image description here

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3
  • Thanks its happening. But, can we display or reclassify the map into 2 classes i.e. forest and other woodland in one classes and remaining land-use in other classes. This will help in making map more meaning to look at and classify according to land-uses. Thanks in advance.
    – Walker
    Jun 12, 2022 at 2:37
  • 1
    Yes, you can. But that's a different question. One question per post.
    – aldo_tapia
    Jun 12, 2022 at 2:57
  • 1
    It should be first crop, then mask (and that is what you show). It is prettier to do crop(r, v, mask=TRUE)
    – Robert Hijmans
    Jun 17, 2022 at 10:34

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