I'm trying to create polygons of specific size in square meters that represent the areas surrounded by roads. The roads are stored in PostGIS as points / lines. If required, I can convert the data to other formats for processing in other softwares like ArcGIS etc.

Because of the randomness of the roads, the polygons could differ in size but their size should not be less than the specified size.

See the below picture. For illustration, I have set different colors to the possible polygons of equal size fulfilling minimum size constraint.

Can somebody please mention how can I achieve this? As I am beginner so sample query or code would greatly help. I have basic know how of PostGIS, QGIS and ArcGIS but I am willing to use any other software if it solves my problem.

enter image description here

If the street network looks like below, polygons like given in red needs to be created (only as an example, in fact all the intersections between streets fulfilling the minimum area constraint should produce polygons like these).

Let suppose we want to create polygons of minimum 2 square kilometer area and let suppose that the area made up of 3 white patches shown in blue is of 2 square kilometer then the code should create a polygon consisting these 3 white patches. You can see that polygon 3 is larger than the polygon 1 but fulfilling the minimum size constraint, similarly polygon 2 has four white patches to fulfill the minimum size constraint.

enter image description here

  • It looks like you want to create polygons of the areas enclosed by roads...? I.e. parcels? Is that area you are talking about actually the parcel size?
    – geozelot
    Commented Feb 11, 2020 at 19:59
  • I want to create polygons of the specific size of the areas enclosed by roads. For example, if the required polygons size is 2km then the code should be able to find the roads which collectively make about 2km polygon.
    – Shuji
    Commented Feb 11, 2020 at 20:06
  • In short, Yes! I want to create polygons of the areas enclosed by roads!
    – Shuji
    Commented Feb 11, 2020 at 20:08
  • So...would it be okay to actually create those polygons using the roads as bounds? No size calacularions involved?
    – geozelot
    Commented Feb 11, 2020 at 20:15
  • 1
    It's polygon grouping task, see this gis.stackexchange.com/questions/123289/…
    – FelixIP
    Commented Feb 12, 2020 at 4:43

1 Answer 1


Tested approach mentioned.Results:

enter image description here

enter image description here

Script posted here should do the job.

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