geosnap.harmonize.harmonize

geosnap.harmonize.harmonize(raw_community, target_year=None, weights_method='area', extensive_variables=None, intensive_variables=None, allocate_total=True, raster='nlcd_2011', codes=[21, 22, 23, 24], force_crs_match=True, index='geoid', time_col='year')[source]

Use spatial interpolation to standardize neighborhood boundaries over time.

Parameters
raw_communitylist of geopandas.GeoDataFrames

Multiple GeoDataFrames given by a list (see (1) in Notes).

target_yearstr

The target year that represents the bondaries of all datasets generated in the harmonization. Could be, for example ‘2010’.

weights_methodstr
The method that the harmonization will be conducted. This can be set to:
  • “area” : harmonization according to area weights.

  • “land_type_area” : harmonization according to the Land Types considered ‘populated’ areas.

  • “land_type_Poisson_regression” : NOT YET INTRODUCED.

  • “land_type_Gaussian_regression” : NOT YET INTRODUCED.

extensive_variableslist

The names of variables in each dataset of raw_community that contains extensive variables to be harmonized (see (2) in Notes).

intensive_variableslist

The names of variables in each dataset of raw_community that contains intensive variables to be harmonized (see (2) in Notes).

allocate_totalbool

True if total value of source area should be allocated. False if denominator is area of i. Note that the two cases would be identical when the area of the source polygon is exhausted by intersections. See (3) in Notes for more details.

rasterstr

the path to the associated raster image that has the types of each pixel in the spatial context. Only taken into consideration for harmonization raster based.

codesan integer list of codes values that should be considered as

‘populated’. Since this draw inspiration using the National Land Cover Database (NLCD), the default is 21 (Developed, Open Space), 22 (Developed, Low Intensity), 23 (Developed, Medium Intensity) and 24 (Developed, High Intensity). The description of each code can be found here: https://www.mrlc.gov/sites/default/files/metadata/landcover.html Only taken into consideration for harmonization raster based.

force_crs_matchbool. Default is True.

Wheter the Coordinate Reference System (CRS) of the polygon will be reprojected to the CRS of the raster file. It is recommended to leave this argument True. Only taken into consideration for harmonization raster based.

Notes

  1. Each GeoDataFrame of raw_community is assumed to have a ‘year’ column Also, all GeoDataFrames must have the same Coordinate Reference System (CRS).

2) A quick explanation of extensive and intensive variables can be found here: http://ibis.geog.ubc.ca/courses/geob370/notes/intensive_extensive.htm

  1. For an extensive variable, the estimate at target polygon j (default case) is:

    v_j = sum_i v_i w_{i,j}

    w_{i,j} = a_{i,j} / sum_k a_{i,k}

    If the area of the source polygon is not exhausted by intersections with target polygons and there is reason to not allocate the complete value of an extensive attribute, then setting allocate_total=False will use the following weights:

    v_j = sum_i v_i w_{i,j}

    w_{i,j} = a_{i,j} / a_i

    where a_i is the total area of source polygon i.

    For an intensive variable, the estimate at target polygon j is:

    v_j = sum_i v_i w_{i,j}

    w_{i,j} = a_{i,j} / sum_k a_{k,j}