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Tool Population Land Cover Views

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Population Land Cover Views

Summary

Estimates the percentage of the population in each reporting unit that have potential views of selected land cover classes within a given distance from their location and creates an output table. A land cover class is visible if it is found within the neighborhood defined by the View radius and in a group of cells larger than or equal to the Minimum visible patch size. The Minimum visible patch size and View radius are provided by the user. The neighborhood is circular in shape.

Additional fields for total population count within the reporting unit, the total population count in the reporting unit with potential views, the total population count in the reporting unit without potential views, and the percentage of the total population in the reporting unit without potential views are also output.

Usage

To be edited.

  • Field names in the Output table are as follows:

    • RU_POP - The population for the reporting unit.

    • [class Id]_PV_C - The population count within the reporting unit with potential views of the selected class (e.g. "for_PV_C" is the name of the field for the population count within the reporting unit with potential views of forest land cover).

    • [class Id]_PV_P - The proportion of the population within the reporting unit with potential views of the selected class (e.g. "for_PV_P" is the name of the field for the proportion of the population with potential views of forest land cover within the reporting unit).

    • [class Id]_MV_C - The population count within the reporting unit with zero or minimal views of the selected class (e.g. "for_PV_C" is the name of the field for the population count within the reporting unit with zero or minimal views of forest land cover).

    • [class Id]_MV_P - The proportion of the population within the reporting unit with zero or minimal views of the selected class (e.g. "for_MV_P" is the name of the field for the proportion of the population with zero or miminal views of forest land cover within the reporting unit).

    • NOTE: Output field names can be altered by editing the Land cover classification file with the Land Cover Classification Editor (Refer to Classes Element in ATtILA's LCC XML Document for general information, or the individual Land cover classification file for details).

    • NOTE: The output field name for each class is shown as the second item next to the class's check box in Report metrics for these classes.

    • NOTE: Only the [class Id]_PV_C field name is presented in the Report metrics for these classes.

  • In Additional Options, the user may elect to 'Retain Intermediate Layers Generated During Metric Processing'.

    • Retain Intermediate Layers Generated During Metric Calculation

      • Choosing INTERMEDIATES retains several of the key intermediate products (e.g., rasters, feature classes, tables) used to generate the final tool output. By examining the intermediate products, the user can gain a better understanding how the metric is calculated. The following intermediate products are listed in the general order they are generated:

        • plcv_[class Id]_ViewPatch_# (raster) - Rasters created from the Land cover grid for each class selected in the Report metrics for these classes parameter of the tool with reclassed values corresponding to the following scheme: 1 = [class Id], 0 = Other.

        • plcv_[class Id]_ViewArea_# (raster) -

        • plcv_[class Id]_ViewAreaPoly_# (vector) -

        • plcv_[class Id]_ViewPopulation_# (raster) -

        • plcv_[class Id]_ViewPopulationByRU_# (vector) -

        • NOTE: To ensure unique filenames, intermediate filenames are typically generated using the CreateScratchName ArcPy function. This function provides a unique name for the intermediate product by appending a number to a filename prefix. The number starts at 0 and is incremented until a unique filename for the output workspace is found. The generated number is represented in this manual by the hashtag (#) symbol.

        • NOTE: The appended number may not be the same for all intermediate products saved during a tool run. Running a tool with different input options can result in different intermediate products being produced. If a tool is run more than once using the same output workspace, different number suffixes may be generated depending on the files already present in the output workspace.

      • Intermediate products are saved to one of the following locations:

        • When the Output table is saved as a File Geodatabase Table, intermediate products are placed in the same file geodatabase.

        • When the Output table is saved as a dBASE Table, a file geodatabase named "attilaScratchWorkspace" is automatically generated in the same output location specified for the Output table. Intermediate products are placed in the attilaScratchWorkspace file geodatabase.

        • NOTE: ATtILA will report the location of the saved intermediate products in the Tool Details' Messages section.

Syntax

PLCV (Reporting_unit_feature, Reporting_unit_ID_field, Land_cover_grid, Land_cover_classification_scheme, Land_cover_classification_file, Report_metrics_for_these_classes, View_radius, Minimum_visible_patch_size, Population_raster, Output_table, {Processing_cell_size}, {Snap_raster}, Select_options)

Parameter Explanation Data Type
Reporting_unit_feature The vector polygon dataset that defines the reporting units. Feature Layer
Reporting_unit_ID_field The field in the Reporting unit feature layer that contains the unique ID for each reporting unit.

It may be an integer or a string data type.		 Field
Land_cover_grid The raster dataset representing land cover classes to be summarized within each Reporting unit feature.

The grid input must be an integer raster layer.		 Raster Layer
Land_cover_classification_scheme The land cover classification schemes included in ATtILA and a User Defined option.

The default schemes correspond to common input land cover datasets. Two schemes are supplied for each dataset included in ATtILA:

  • {DATASET NAME} ALL - includes all land cover types in the grid with no exclusions.
  • {DATASET NAME} LAND - excludes non-terrestrial land cover types.
 String
Land_cover_classification_file The full pathname to the user-defined .xml file for custom or non-standard land cover classification schemes.

Pathname is automatically filled when a default scheme is selected.		 File
Report_metrics_for_these_classes A list of the land cover classes and metric combinations for processing.

Check the box to calculate metrics for each land cover class and/or combination class desired within the reporting units.		 Multiple Value
View_radius The radius of the view neighborhood, measured in number of grid cells. The neighborhood is circular in shape.

The input must be an integer value.		 Long
Minimum_visible_patch_size The minimum patch size, measured in number of grid cells, necessary to be considered a visible patch.

Connectivity is defined within the immediate eight-cell neighborhood. Cells of the same class to the right, left, above, below, or diagonal to each other are considered as part of the same patch.

The input must be an integer value.		 Long
Population_raster The raster dataset that contains population data.

The grid input can be either an integer or floating-point raster layer.		 Raster Layer
Output_table The output reporting unit metrics table to be created.

It is recommended that the Output table be saved within a file geodatabase.		 Table
Select_options (Optional) One tool option is available to provide additional information:

  • Retain Intermediate Layers Generated During Metric Calculation - Saves the intermediate data layers that are normally deleted after processing is complete.
 Multiple Value

Code Samples

Population Land Cover Views example 1 (Python window)

This example returns a table with the percentage of the population in each reporting unit that have potential views of forest land cover within 50 meters from their location. The forest class is visible if it is in a group of cells larger than or equal to one cell. Additional fields for total population count within the reporting unit, the total population count in the reporting unit with potential views, the total population count in the reporting unit without potential views, and the percentage of the total population in the reporting unit without potential views are also output.

NOTE: ATtILA tools that utilize the Report metrics for these classes parameter will clear all class selections when the tool is opened. This results in setting any variable set for that parameter to None when calling the tool from a script. Because of this, the standard scripting syntax (e.g. arcpy.ATtILA.LCP(variable 1, variable 2, variable 3, etc.) will fail. To overcome this idiosyncrasy, use the scripting example provided below. When using this technique, all variables are passed in as strings.

import arcpy
from arcpy.sa import *
arcpy.ImportToolbox(r"D:\Destination Folder\ATtILA v2.tbx")
from ATtILA2 import metric

Reporting_unit_feature = r"D:\pyexamples\data.gdb\Blockgroups"
Reporting_unit_ID_field = "bgrp"
Land_cover_grid = r"D:\pyexamples\data.gdb\MULC_2017"
Land_cover_classification_scheme = "MULC Blended Levels ALL"
Land_cover_classification_file = r"D:\Destination Folder\ToolboxSource\LandCoverClassifications\MULC Blended Levels ALL.xml"
Report_metrics_for_these_classes = "'for  -  [for_PV_C]  Trees/Forest, and Woody Wetlands'"
View_radius = "50"
Minimum_visible_patch_size = "1"
Population_raster = r"D:\pyexamples\data.gdb\DASY_Population"
Output_table = r"D:\pyexamples\results.gdb\Blockgroup_PLCV"
Processing_cell_size = "1"
Snap_raster = r"D:\pyexamples\data.gdb\MULC_2017"
Select_options = "'INTERMEDIATES  -  Retain Intermediate Layers Generated During Metric Calculation'"

metric.runPopulationLandCoverViews(Reporting_unit_feature,
                                   Reporting_unit_ID_field,
                                   Land_cover_grid,
                                   Land_cover_classification_scheme,
                                   Land_cover_classification_file,
                                   Report_metrics_for_these_classes,
                                   View_radius,
                                   Minimum_visible_patch_size,
                                   Population_raster,
                                   Output_table,
                                   Processing_cell_size,
                                   Snap_raster,
                                   Select_options)

Population Land Cover Views example 2 (Tool Details Messages)

This is a sample capture of the geoprocessing messages generated during a typical tool run. It is provided here to assist in the understanding of the tool's processing steps.


Start Time: Day, Month dd, yyyy hh:mm:ss AM/PM
Started: yyyy-mm-dd hh:mm:ss Setting up environment variables
Intermediates are stored in this directory: workspace path
Time: yyyy-mm-dd hh:mm:ss Calculating population within each reporting unit
Time: yyyy-mm-dd hh:mm:ss Reclassifying selected land cover class, FOR, to 1. All other values = 0...
Time: yyyy-mm-dd hh:mm:ss Save intermediate grid complete: plcv_FOR_ViewPatch_0
Time: yyyy-mm-dd hh:mm:ss Performing focal SUM on patches of FOR using 50 cell radius neighborhood...
Time: yyyy-mm-dd hh:mm:ss Reclassifying focal SUM results into a single-value raster where 1 = potential view area...
Time: yyyy-mm-dd hh:mm:ss Save intermediate grid complete: plcv_FOR_ViewArea_0
Time: yyyy-mm-dd hh:mm:ss Converting view raster to a polygon feature
Setting geoprocessing environmental parameters for snap raster and cell size to match population raster
Time: yyyy-mm-dd hh:mm:ss Extracting population pixels within the potential view area...
Time: yyyy-mm-dd hh:mm:ss Save intermediate grid complete: plcv_FOR_ViewPopulation_0
Time: yyyy-mm-dd hh:mm:ss Calculating population within minimal-view areas for each reporting unit
Restoring snap raster geoprocessing environmental parameter to original setting
Restoring cell size geoprocessing environmental parameter to original setting
Time: yyyy-mm-dd hh:mm:ss Calculation complete
Succeeded at Day, Month dd, yyyy hh:mm:ss AM/PM (Elapsed Time: ##.## units)

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