Low Income Population Concentration - Sierra Nevada

Relative concentration of the estimated number of people in the Sierra Nevada region that live in a household defined as "low income." There are multiple ways to define low income. These data apply the most common standard: low income population consists of all members of households that collectively have income less than twice the federal poverty threshold that applies to their household type. Household type refers to the household's resident composition: the number of independent adults plus dependents that can be of any age, from children to elderly. For example, a household with four people '€“ one working adult parent and three dependent children '€“ has a different poverty threshold than a household comprised of four unrelated independent adults.

Due to high estimate uncertainty for many block group estimates of the number of people living in low income households, some records cannot be reliably assigned a class and class code comparable to those assigned to race/ethnicity data from the decennial Census.

"Relative concentration" is a measure that compares the proportion of population within each Census block group data unit to the proportion of all people that live within the 775 block groups in the Sierra Nevada RRK region. See the "Data Units" description below for how these relative concentrations are broken into categories in this "low income" metric.

Data and Resources

Additional Info

Field Value
Version Version 5.0
Last Updated March 28, 2025, 08:35 (UTC)
Created March 7, 2025, 07:52 (UTC)
categorical_values {"3": 4179661, "5": 4737476, "99": 5119119, "2": 5923700, "6": 1697718, "1": 4855435, "4": 3058424, "7": 10777, "0": 160877}
category /Social and Cultural Well-Being/Equitable Opportunity/Low Income Population Concentration
collection_name California Landscape Metrics
creation_method Data are reported in Census block groups. Standard block groups are clusters of Census blocks within the same census tract that have the same first digit of their 4-character census block number (e.g., Blocks 3001, 3002, 3003 to 3999 in census tract 1210.02 belong to block group 3). Block groups delineated for the 2020 Census generally contain 600 to 3,000 people. Census blocks are statistical areas bounded on all sides by visible features (e.g., streets, roads, streams, and railroad tracks), and by non-visible boundaries (e.g., city, town, township, county limits, and short line-of-sight extensions of streets and roads). Census blocks in suburban and rural areas may be large, irregular, and bounded by a variety of features (e.g., roads, streams, and/or transmission line rights-of-way). In remote areas, census blocks may encompass hundreds of square miles. Census blocks cover all territory in the United States, Puerto Rico, and the Island areas. Blocks do not cross the boundaries of any entity for which the Census Bureau tabulates data. See note 1. Data describing concentrations of population characteristics that are potentially related to environmental justice issues were provided to CWI through a collaboration with the USDA Forest Service, Geospatial Technology and Applications Center. The concentration methodology was created by GTAC for social science analysis applications within the Forest Service; it is based on research published in 2018 and 2020 (See Note 2). Data were compiled and prepared for incorporating in the Task Force Regions by Mark Adams, Geographer, USFS-GTAC. For more information, contact: [mark.adams1@usda.gov](mailto:mark.adams1@usda.gov). Notes: The pixels attributed with a categorical data unit describing the relative concentration of LOW_INCOME population are derived from a vector polygon feature that has been modified as follows: Census block groups from the Census Bureau's TIGER/Line geodatabase features for 2021 are selected based on their spatial intersection with the Sierra Nevada RRK boundary. The resulting 775 block group features are modified by first erasing from the feature the area of all constituent Census blocks which have neither housing nor population recorded in the PL-94171 Redistricting dataset for 2020. In a second step, areas of federal and state public lands on which housing by definition is not located are erased from the interim feature. The result is a block group feature that depicts to the maximum practicable extent the areas within the block group where people that are represented by the Census Bureau's Census count could actually be residing. It is this modified block group feature that has been rasterized to match the 30m pixel grid that all biophysical datasets are reported in. References for the concentration levels analysis: \- Adams, Mark D. O. and S. Charnley. 2020. The Environmental Justice Implications of Managing Hazardous Fuels on Federal Forest Lands, Annals of the American Association of Geographers, 110:6, 1907-1935, DOI: 10.1080/24694452.2020.1727307 \- Adams, Mark D. O. and S. Charnley. 2018. Environmental justice and U.S. Forest Service hazardous fuels reduction: A spatial method for impact assessment of federal resource management actions. https://doi.org/10.1016/j.apgeog.2017.12.014
data_resolution 30m Raster
data_units Categorical
data_vintage 2020
date_updated August 2024
element Equitable Opportunity
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file_name SNV_LowIncome_2020_202406_T2_v5
format GeoTiff
harvest_object_id 53267bdb-d6fe-461b-8df1-c8cec9c4aa9d
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 99.0
metric_definition_and_relevance Relative concentration of the estimated number of people in the Sierra Nevada region that live in a household defined as "low income." There are multiple ways to define low income. These data apply the most common standard: low income population consists of all members of households that collectively have income less than twice the federal poverty threshold that applies to their household type. Household type refers to the household's resident composition: the number of independent adults plus dependents that can be of any age, from children to elderly. For example, a household with four people '€“ one working adult parent and three dependent children '€“ has a different poverty threshold than a household comprised of four unrelated independent adults. Due to high estimate uncertainty for many block group estimates of the number of people living in low income households, some records cannot be reliably assigned a class and class code comparable to those assigned to race/ethnicity data from the decennial Census. "Relative concentration" is a measure that compares the proportion of population within each Census block group data unit to the proportion of all people that live within the 775 block groups in the Sierra Nevada RRK region. See the "Data Units" description below for how these relative concentrations are broken into categories in this "low income" metric.
minimum_value 0.0
pillar Social and Cultural Well-Being
spatial {"type": "Polygon", "coordinates": [[[-122.28837036754696, 35.05769372687348], [-117.55631977151295, 35.05769372687348], [-117.55631977151295, 42.003593546357536], [-122.28837036754696, 42.003593546357536], [-122.28837036754696, 35.05769372687348]]]}
sub_element Low Income Population Concentration
tier 2