Variables required by hydrosheds_download.sh
NB the example values would download the conditioned DEM for the whole of India

*product
Void-filled DEM/Conditioned DEM/Flow direction at 3sec/15sec/30sec. Format is as follows:
sa_(dem|con|dir)_(3s|15s|30s)_grid
where you should select one of dem/con/dir and one of 3s/15s/30s
e.g. product=sa_con_15s_grid

*continent
Select one of the following:
'AF' (Africa)
'AS' (Asia)
'au' (Australia)
'CA' (Central America, Caribbean, Mexico)
'EU' (Europe)
'NA' (United States, Canada)
'SA' (South America)
e.g. continent=AS

*lon_hemisphere
Select one of the following:
'e' (East)
'w' (West)
e.g. lon_hemisphere=e

*lat_hemisphere
Select one of the following:
'n' (North)
's' (South)
e.g. lat_hemisphere=n

*lon0
First longitudinal boundary (lon0 < lon1)
Valid longitude values are 0, 5, 10, ..., 180
e.g. lon0=65

*lon1
Second longitudinal boundary
e.g. lon1=100

*lat0
First latitudinal boundary (lat0 < lat1)
Valid latitude values are 0, 5, 10, ..., 90
e.g. lat0=5

*lat1
Second latitudinal boundary
e.g. lat0=35

*safemode
Either TRUE or FALSE. If TRUE, the program checks for the existence of each 
file but does not download them.
e.g. safemode=FALSE

*path
The destination directory
e.g. path=/home/simon/hydrosheds/conditioned_dem