2

How do I draw a grid of n by n on the shapefile of a city with a CRS of EPSG:4326?

I have tried creating gird in ESPG:32735

Image with EPSG:32735

I have created a grid using this.

Vector -> Research Tools -> Vector Grid

But when I try to export it as EPSG:4326, this grid gets stretched, and I can't use it in python.

Multiple tries that I did

SAGA -> Vector general -> Create polygons graticule
MMQGIS -> Create -> Create Grid Layer

Image with EPSG:4326


Python result

python stretched grdi

temp_shapefile = gpd.read_file('../temp/tempgrid.shp') <br>
fig,ax = plt.subplots(figsize = (15,15)) <br>
temp_shapefile.boundary.plot(ax=ax, alpha = 0.4, color="black") <br>
df_Selected.plot(ax=ax, markersize = 15,color = "black", legend=True) 
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  • 4
    don't use 4326 for analysis - stick with the local projection
    – Ian Turton
    Aug 11 at 15:36
  • If I stick to the system 32735, I can't draw that in Python Aug 12 at 8:51
  • why not? any reasonable mapping library should handle that projection
    – Ian Turton
    Aug 12 at 9:15
2

The grid gets distorted when you change the projection of the map (see here for details). Create the grid in the projection you want to use for the output, thus in your case in EPSG:4326 (WGS84). As units in this projection are in degrees, however, you should calculate an appropriate value for the grid distance.

See @Ian Turton's comment, however: don't use 4326 for analysis.

0

Create your grid in EPSG:3857 (aka Web Mercator), then reproject to WGS84 and save.

1
  • 5
    Web Mercator doesn't support accurate distance measurement. That makes it inappropriate for grid generation.
    – Vince
    Aug 11 at 18:39

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