This PR slightly changes our methodology for reporting total, surface, and subsurface state trust land acreage on reservations. Previously, we reported numbers that were the sum of all parcels' clipped_acres values. However, we noticed that, in certain states, some of these parcels may have partial or near complete overlap. This meant that areas of overlap would effectively be double-counted.
To avoid double-counting overlapping acreage, our aggregation script now does the following:
When computing total rights_type acreage (i.e., surface or subsurface acres), we compute the geometric area of the unioned MultiPolygon created by gpd.dissolve. In effect, all state trust lands of a given rights_type on a given reservation are turned into one large MultiPolygon, "dissolving" any areas of overlap.
We compute total acreage by summing the dissolved surface and subsurface acreage numbers.
In general, this only changes our numbers significantly in MT, but we do see some slight drops in MN and OK as well.
This PR slightly changes our methodology for reporting total, surface, and subsurface state trust land acreage on reservations. Previously, we reported numbers that were the sum of all parcels'
clipped_acresvalues. However, we noticed that, in certain states, some of these parcels may have partial or near complete overlap. This meant that areas of overlap would effectively be double-counted.To avoid double-counting overlapping acreage, our aggregation script now does the following:
MultiPolygoncreated bygpd.dissolve. In effect, all state trust lands of a given rights_type on a given reservation are turned into one largeMultiPolygon, "dissolving" any areas of overlap.In general, this only changes our numbers significantly in MT, but we do see some slight drops in MN and OK as well.