Collaborative Research: The National Historical Geographic Information System

从2001年到2007年，明尼苏达大学和其他机构的研究人员一直在组装国家历史地理信息系统(NCGIS)。NHGIS的设计目的是在一个地理信息系统框架内访问丰富的汇总人口普查数据。项目目标是收集1790年至2000年所有幸存的普查数据，统一格式，为这些数据编写全面的标准化机器可读文件，创建描述人口普查地区和县的高精度历史电子边界文件，并开发用于传播统计数据、地理数据和元数据的创新网络工具。然而，随着项目最初目标的实现，新的机会出现了。根据过去五年提供的新地理标准和统计基础设施，更新和改进国家地理信息系统的工作将通过升级国家地理信息系统来继续进行。特别是，该项目将重新调整NHGIS边界文件，以确保与新标准的兼容性。由于人口普查局正在大幅修订其TIGER/LINE文件以提高准确性，NHGIS文件将重新调整，以便历史数据将与新发布的地理信息系统数据同步。国家地理信息系统管理人员还将把地理水平添加到国家地理信息系统1980年至2000年的文件中，以确保这些数据仍然可供研究人员使用。新的NHGIS地理位置将包括街区、地点、枚举区、国会区和邮政编码制表区。NHGIS管理者还将把美国社区调查(ACS)纳入NHGIS。为了利用ACS提供的连续数据收集的可能性，而且数据是连续收集的，而不是在特定的普查日收集数据，并且汇总统计的参考期根据地理单位的人口规模而不同，将这些数据纳入NHGIS将需要开发创新的元数据和软件。新的活动还将提供用户支持和传播，新的地图和数据将被添加到NHGIS在线地图应用程序Social Explorer中。NHGIS的不断完善将使这一资源能够加快人口普查民主化进程。该数据库正被广泛用于社会科学培训、媒体、州和地方各级的政策研究以及私营部门。国家地理信息系统数据库将越来越多地用于基础社会科学研究，扩大地方和区域分析的范围，以同时探索跨越时间和空间的变化。

From 2001 through 2007, researchers at the University of Minnesota and other institutions have been assembling the National Historic Geographic Information System (NCGIS). The NHGIS was designed to make the rich body of aggregate census data accessible within a GIS framework. Project goals were to gather all surviving census data from 1790 to 2000, format them consistently, develop comprehensive standardized machine-readable documentation for those data, create high-precision historical electronic boundary files describing census tracts and counties, and develop innovative web-based tools for disseminating statistical data, geographic data, and metadata. As the project's original goals were attained, however, new opportunities had presented themselves. This renewal award will support continued work to update and improve the NHGIS by upgrade the NHGIS system in response to new geographic standards and statistical infrastructure that have become available during the last five years. In particular, the project will realign NHGIS boundary files to ensure compatibility with new standards. Because the Census Bureau is substantially revising its TIGER/Line files to improve accuracy, NHGIS files will be realigned so that the historical data will be synchronized with new GIS data releases. NHGIS managers also will add geographic levels to NHGIS files for 1980 through 2000 to ensure that these data remain available to researchers. The new NHGIS geographies will include block, place, enumeration district, congressional district, and Zip Code Tabulation Areas. NHGIS managers also will incorporate the American Community Survey (ACS) into NHGIS. In order to take advantage of the continuous data-collection possibilities offered by the ACS but also data are collected continuously instead of on a specified census day and the reference period for aggregate statistics varies according to the population size of the geographic unit, incorporating these data into NHGIS will require development of innovative metadata and software. New activities also will provide user support and dissemination, and the new maps and data will be added to the NHGIS online mapping application, Social Explorer.Continued refinement of the NHGIS will permit this resource to accelerate the process of democratizing access to the census. The database is being used widely for social science training, by the media, for policy research at the state and local levels, and by the private sector. The NHGIS database will be increasingly accessible for basic social science research, broadening the scope of local and regional analyses to explore variations across time and space simultaneously.