2020 Census Municipal Boundaries with Philly Planning Districts; DVRPC Region

DVRPC manually adjusted TIGER MCD dataset by adding Philly Planning District boundaries. To get the Planning District boundaries, census tracts were dissolved into most appropriate CPA geography. (Planning Districts are sometime referred to as County Planning Areas at DVRPC) Updated in Jan 2023 to reflect Pine Valley/Pine Hill merger (Pine Valley was incorporated into Pine Hill) The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Census tracts are small, relatively permanent statistical subdivisions of a county or equivalent entity, and were defined by local participants as part of the 2020 Census Participant Statistical Areas Program. The Census Bureau delineated the census tracts in situations where no local participant existed or where all the potential participants declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of census data and comparison back to previous decennial censuses. Census tracts generally have a population size between 1,200 and 8,000 people, with an optimum size of 4,000 people. When first delineated, census tracts were designed to be homogeneous with respect to population characteristics, economic status, and living conditions. The spatial size of census tracts varies widely depending on the density of settlement. Physical changes in street patterns caused by highway construction, new development, and so forth, may require boundary revisions. In addition, census tracts occasionally are split due to population growth, or combined as a result of substantial population decline. Census tract boundaries generally follow visible and identifiable features. They may follow legal boundaries such as minor civil division (MCD) or incorporated place boundaries in some States and situations to allow for census tract-to-governmental unit relationships where the governmental boundaries tend to remain unchanged between censuses. State and county boundaries always are census tract boundaries in the standard census geographic hierarchy. In a few rare instances, a census tract may consist of noncontiguous areas. These noncontiguous areas may occur where the census tracts are coextensive with all or parts of legal entities that are themselves noncontiguous. For the 2010 Census, the census tract code range of 9400 through 9499 was enforced for census tracts that include a majority American Indian population according to Census 2000 data and/or their area was primarily covered by federally recognized American Indian reservations and/or off-reservation trust lands; the code range 9800 through 9899 was enforced for those census tracts that contained little or no population and represented a relatively large special land use area such as a National Park, military installation, or a business/industrial park; and the code range 9900 through 9998 was enforced for those census tracts that contained only water area, no land area. See https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc_Ch3.pdf for more information Downloaded from: https://www2.census.gov/geo/tiger/TGRGDB20/ on August 13, 2020特拉华谷区域规划委员会（DVRPC）手动调整了TIGER次级民政分区（MCD）数据集，新增费城规划区（Philly Planning District）边界。为获取规划区边界，将人口普查街区组（census tracts）聚合为最适配的社区规划区（CPA）地理单元。（在DVRPC体系中，规划区有时也被称为县级规划区）本数据集于2023年1月更新，以反映派恩谷（Pine Valley）与派恩希尔（Pine Hill）的合并情况（原派恩谷已并入派恩希尔）。 TIGER/Line形状文件（TIGER/Line shapefiles）及相关数据库文件（.dbf）是美国人口普查局主地址文件/拓扑集成地理编码与参考（MAF/TIGER）数据库（MTDB）中精选地理与制图信息的提取子集。 MTDB是一套无缝衔接的全国性数据集，各部分之间无重叠或空隙；但每个TIGER/Line形状文件均可作为独立数据集单独使用，也可组合使用以覆盖全美范围。 人口普查街区组是县或等效行政单元下规模较小、相对稳定的统计分区，由本地参与方作为2020年人口普查参与者统计区域计划的一部分划定。若不存在本地参与方，或所有潜在参与方均拒绝参与，则由美国人口普查局自行划定人口普查街区组。 人口普查街区组的核心用途是提供一套稳定的地理单元，用于呈现人口普查数据，并与历次十年一次的人口普查数据进行对比。 人口普查街区组的人口规模通常介于1200至8000人之间，最优规模为4000人。初次划定之时，街区组的设计初衷是在人口特征、经济状况与居住条件方面保持同质性。 人口普查街区组的空间尺度差异极大，取决于定居点的人口密度。由高速公路建设、新开发项目等导致的街道格局实体变化，可能需要对街区组边界进行修订。此外，人口增长有时会导致街区组被拆分，而人口大幅减少则可能促使相邻街区组合并。 人口普查街区组的边界通常遵循可见且可识别的地物。在部分州的特定场景中，边界也可遵循次级民政分区（MCD）或已建制地区的法定边界，以便建立街区组与行政单元之间的对应关系——这类行政边界在两次人口普查之间通常保持稳定。在标准的人口普查地理层级体系中，州界与县界始终同时作为人口普查街区组的边界。 极少数情况下，人口普查街区组可能由非连片区域组成。此类非连片区域的出现场景通常为：该街区组与某个本身即为非连片的法定实体的全部或部分区域范围重合。 针对2010年人口普查，以下三类街区组使用特定的编码区间：1. 基于2000年人口普查数据，美洲原住民人口占多数的街区组，或其区域主要为联邦认可的美洲原住民保留地/保留地外信托土地的街区组，编码区间为9400至9499；2. 人口极少或无人口，且对应较大规模特殊土地用途区域（如国家公园、军事设施、商业/工业园区）的街区组，编码区间为9800至9899；3. 仅包含水域、无陆地面积的街区组，编码区间为9900至9998。 详细信息可参阅文档：https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc_Ch3.pdf。本数据集于2020年8月13日从https://www2.census.gov/geo/tiger/TGRGDB20/ 下载获取。