Alpha transparency not uniform when plotting a shapefile with Geopandas

Question

When plotting a shapefile with Geopandas, I need to make the features transparent. When applying an alpha parameter, some of the features become less transparent than others.

fig = plt.figure(figsize = (8.5,11))
ax =fig.add_axes([0.05,0.15,.9,.8])

mapDF = gpd.read_file('hydrography.shp')

mapDF.plot(color=('steelblue'), ax=ax, alpha=0.5)

I expected all the features to have uniform transparency, but some features are noticeably more transparent than others. There is nothing different about those features.

Please click here to see what I am describing.

Does anyone know a way to fix this? Thank you.

I suspect that some features are plotted on top of the others. — swatchai, Aug 16 '19 at 04:49
Thank you! I checked in ArcMap, and you are absolutely right. — etotheipi, Aug 19 '19 at 19:31
You can turn your comment into your own answer, and click to accept it. If your writing is nice, I will upvote the answer. — swatchai, Aug 31 '19 at 03:14

score 3 · Answer 1 · answered Sep 01 '19 at 04:10

3

As swatchai had suggested, my shapefile had multiple features stacked upon one another; thus the transparency was reduced. I deleted the overlapping features, and the problem was solved.

answered Sep 01 '19 at 04:10

etotheipi

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Alpha transparency not uniform when plotting a shapefile with Geopandas

1 Answers1