Description:

Abstract:

The Baltimore-Washington Spatial Dynamics and Human Impacts data set is an integrated and flexible temporal urban land characteristics database for the Baltimore-Washington metropolitan area. The compilation of this data is a collaborative effort led by the U.S. Geological Survey and the University of Maryland Baltimore County. The database provides visual and historical perspective of the urban growth experienced in the area between 1792 and 1992. The multi-theme temporal database includes urban development, principal transportation, hydrography, census and legal/statistical boundaries as a framework for regional spatial data analysis. The datasets for a 15-minute square area centered on Baltimore, Maryland consist of coverages for hydrography (1801, 1822, 1878, and 1890), built-up areas (1801, 1822, 1878, and 1890), and principal transportation (1801, 1822, 1878, and 1890). The dataset for a 2-degree by 2-degree area that includes most of Maryland as well as parts of Virgina, Pennsylvania and West Virginia includes coverages for hydrography (1792, 1850, and 1900), including a coverage which shows reserviors as they come into existence; built-up areas (1792, 1850, 1900, 1925, 1938, 1953, 1966, 1972, 1982, and 1992); and principal transportation, including roads (1792, 1850, 1900, 1925, 1938, 1953, 1966, 1972, 1982, and 1992), railroads (1850, 1900, 1925, 1938, 1953, 1966, 1972, 1982, and 1992); and water transportation (1792, 1850, and 1900). The urban coverages are separated into a different coverage for each time shot. Transportation data are grouped into 3 different coverages, each coverage containing the information for several different time shots, where the separate years may be selected out through the attribute tables. Temporal urban mapping reconstructs past landscapes by incorporating historic maps, census statistics, and commerce records to generate a progressive geo-referenced picture of the past changes in a region. Contemporary mapping focuses on the use of remotely sensed data, existing digital land use data, digital census information, and a variety of earth science infrastructure data, such as Digital Line Graphs, Digital Elevation Models, and key ancillary demographic information. Different procedures were used for different time periods, more fully described for each file in the Process Step section. Additional data sets will be added to the framework, including remotely sensed data from NASA's OES program. The resulting database of temporal urban land use/land cover and demographic changes provides an ideal source of test data and information for both urban geographers and global change research scientists.

Purpose:

This data was developed to illustrate and investigate the spatial patterns and interactions among the physiographic, ecological, and socio-economic variables linked to urban growth. This data conveys in a visual form the critical elements, spatial patterns, and rates of change in urban areas. Historical overviews of urban development provide requesit background for insights into the future. This database will be of much use to urban and regional planners, policy and decision makers, Earth scient ists, and global change researchers for measuring trends in urbanization phenomena including urban sprawl, analyzing patterns of water pollution, understanding the impacts of development on ecosystems, and developing predictive modeling tcchniques to bett er forecast future areas of urban growth. The impact urban land has on economic and environmental systems is extremely large compared to its spatial extent. It is imperative that we understand the determinants of land use (demographics, technology, level s of affluence, etc.) so that future patterns of land use and land cover can be projected and planned.

Supplemental_Information:

The urban development data set consists of polygons representing the extent of built-up areas for the specified time frame. Urban development is broadly defined as areas of intensive use, with much of the land cleared of natural vegetation and occupied with anthropogenic structures. The extent of the built-up areas are defined by the existence of a systematic street pattern, and the relative concentration of buildings and associated intensive use areas. The generalized urban boundary may contain any undeveloped land that is completely surrounded by developed areas. The urban area includes parks, golf courses, and any other area whose natural vegetation has been significantly altered. The classification scheme adopted for this study is a modification of the land use and land cover classification system described by Anderson and others (1976). The classification definitions were modified slightly to accommodate limitations in the source materials and to meet the data requirements for studying the regional and temporal aspects of human-induced land transformations. The full classification scheme can be found in the Entity and Attribute Overview section. The data are available in three files (See Online Linkages).