Update README.md

README.md

@@ -33,7 +33,7 @@ You must install the following softwares and packages :
 - [R Version 3.2.3](https://cran.r-project.org/)
     - [R-package]ggplot2 `install.packages("ggplot2")`
     - [R-package]rgeos `install.packages("rgeos")`
-    - [R-package]rgdal please download rgdal at (https://cran.r-project.org/web/packages/rgdal/index.html) and then `install.packages("~/Downloads/rgdal_1.1-10.tar.gz")`
+    - [R-package]rgdal `install.packages("rgdal")` it may require to install `libgdal-dev`
     - [R-package]nodiv `install.packages("nodiv")`
     - [R-package]raster `install.packages("raster")`
     - [R-package]lme4 `install.packages("lme4")`