Census Tracts

The units of geography used for the 2010 Census maps displayed here are the Census tracts. 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. Census tract boundaries generally follow visible and identifiable features. 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. The data collected on the short form survey are general demographic characteristics such as age, race, ethnicity, household relationship, housing vacancy and tenure (owner/renter).

本次展示的2010年人口普查地图所采用的地理单元为普查分区（Census tract）。普查分区的人口规模通常介于1200至8000人之间，最优规模为4000人。在最初划定之时，普查分区的设计目标是在人口特征、经济状况与居住条件方面保持同质性。普查分区的边界通常依托清晰可辨的地理标识划定。在标准普查地理层级体系中，州界与县界始终作为普查分区的边界。仅在极少数例外情况下，单个普查分区可能由不连续的区域组成。人口普查短表调查所收集的数据为通用人口统计特征，涵盖年龄、种族、族裔、家庭关系、住房空置情况以及住房保有形式（自有/租赁）。