Analyzing Land Use Change in Urban Environments

Analyzing Land Use Change In Urban Environments

Metropolitan areas in the United attributed to increasing population. about the effects that unchecked States are growing at unprecedented Cities have changed from small, iso- urbanization has on the landscape. In rates, creating extensive urban land- lated population centers to large, inter- 1998, more than 200 communities scapes. Many of the farmlands, wet- connected economic, physical, and across the Nation voted on, and the lands, forests, and deserts that formed environmental features. vast majority adopted, measures to the America of 1900 have been trans- manage urban sprawl. The UDR pro- formed during the past 100 years into Urban growth and the concentration gram provides basic data, predictions, human settlements. Almost everyone of people in urban areas are creating and perspectives to help in forming has seen these changes to their local societal problems world-wide. One sound policies for guiding environ- environment but without a clear hundred years ago, approximately 15 mentally sustainable growth. understanding of their impacts. It is percent of the world's population was not until we study these landscapes living in urban areas. Today, the per- Mapping Land Use Change from a spatial perspective and the centage is nearly 50 percent. In the time scale of decades that we can last 200 years, world population has Databases developed by the UDR pro- begin to measure the changes that increased six times, stressing ecologi- gram contain interpretations of urban have occurred and predict the impact cal and social systems. Over that same extent, transportation routes, water of changes to come. time period, the urban population has features, and other important land increased 100 times, concentrating uses. Selected regional studies are cur- The U.S. Geological Survey's (USGS) more people on less land even as the rently in progress across the Nation. Urban Dynamics Research (UDR) total land devoted to urbanization Data source availability for each program studies the landscape trans- expands. Yet the temporal and spatial region, in conjunction with historical formations that result from the growth dimensions of the land use changes significance, determines the time peri- of metropolitan regions over time. that shape urbanization are little ods that are mapped. Features are Using sources such as historic maps, known, even in the United States. interpreted from diverse data sources aerial photographs, and Landsat satel- including historical topographic maps, lite data, USGS scientists first assem- In the United States, policymakers and satellite images, census statistics, and ble retrospective urban land use data- the public continue to raise concerns aerial photographs. The resulting tem- bases that reflect several decades of change. These databases are then used to analyze the effects of urbanization on the landscape, and to model urban growth and land use change under alternative growth scenarios.

Land Use Change

Most major metropolitan areas face the growing problems of urban sprawl, loss of natural vegetation and open space, and a general decline in the extent and connectivity of wet- lands and wildlife habitat. The public identifies with these problems when they see residential and commercial development replacing undeveloped land around them. Urban growth rates show no signs of slowing, especially Nearly 80 percent of U.S. residents live in urban areas. This map, compiled from nighttime imagery acquired when viewed at the global scale, since by the Defense Meteorological Satellite Program, shows city lights for urban areas in red for the contermi- these problems can be generally nous United States in 1995.

U.S. Department of the Interior USGS Fact Sheet 188-99 Printed on recycled paper U.S. Geological Survey November 1999 The existence and accessibility of Longview Longview transportation routes have often dic- tated patterns of urban growth. Urban Vancouver Vancouver Vancouver areas that were established in the 18th

Portland and early 19th centuries were usually Portland Portland located along waterways, reflecting dependence on shipping for the trans- Salem Salem Salem port of goods and people. By the middle of the 19th century, railroads began to connect existing towns and spurred the growth of new urban

Eugene Eugene Eugene areas. The post-World War II era saw not Longview Longview Longview only an increase in the population of most metropolitan areas, but also the Vancouver Vancouver Vancouver emergence of a society dependent on

Portland the automobile. The proliferation of Portland Portland the private automobile led to expan- sive development at the edges of Salem Salem Salem many urban areas. The development of the Interstate Highway system in the 1950's spurred the widespread construction of roads. As road net- works expanded and became more Eugene Eugene Eugene complex, urban development fol- lowed. As in the past, most recent This time series documents urban change in the Willamette Valley region over 115 years. The background in each map is a shaded-relief image. The red areas represent urban extent for each time period. The Pacific urban growth has occurred along Ocean and the Columbia River are shown in blue. This study region extends from southern Washington south transportation corridors. to Eugene, OR. Within Oregon, politically defined urban growth boundaries have been in place since the early 1970's in an attempt to control urban expansion. The UDR program provides the data and geographic information necessary poral database is a spatial record of This analysis requires understanding a to document past land use change. By the pace and extent of the urbaniza- region's land use history. Population looking to the past, communities and tion process. data, timelines of historical events, regions are better informed and and related information are all used to A temporal database can be visualized explain the mapped changes. as a sequence of maps, such as those Population data are correlated with shown above and on the next pages, the temporal database so that human or as computer animations. Sequential movement can be tracked and fac- maps show urbanization as a static tored into these interpretations. pattern that changes with each time Population increases suggest econom- period that is mapped. Animations ic growth and the availability of jobs illustrate the temporal dynamics, in an area, and population declines revealing patterns and trends that are suggest a decline in livability or eco- not possible to discern from tabular nomic issues that cause people to data or static maps. leave a region. Timelines of past events and other historical compila- Understanding Land Use Change tions aid in identifying the issues that affected the development of the The geographic understanding of land region. use change in urban areas is a key aspect of the UDR program. By ana- In addition to gathering statistical and lyzing a temporal database for spatial historical information, scientists must patterns, rates of change, and trends, have a physiographic understanding the UDR program can provide insight of the place and its greater region. into how cities have developed under Topographic features, climate, and This preliminary interpretation of urban land use varying social, economic, and envi- adequate supplies of water and other change for Chicago-Milwaukee shows urban growth in 1955, 1975, and 1995. Each time period is repre- ronmental conditions. natural resources can limit or encour- sented by a different color. Black shows the extent age growth and change. of urban growth in 1955, red represents 1975, and yellow represents 1995. equipped to plan and prepare for the By evaluating trends associated with water pollution Ð a problem common future. land use change over time, solutions to urban areas, industrial sites, and to traffic congestion may be obtain- agricultural lands. The amount and Land Use Change Modeling able. degree of water pollution in rivers, lakes, and bays can be predicted on Historical land use patterns, together Another specific application of UDR the basis of past and future trends in with current trends in a region, are data is the correlation of air pollution land use change. A study currently used to model future land use. records with the temporal database to underway in the Patuxent River Basin Results from modeling urban growth determine if control strategies for in Maryland focuses on the sources of and land use change can be used by reducing pollution have been effec- water pollution over time. In this the public, land use planners, and pol- tive. Many pollution control strategies study, temporal change maps of icy makers to anticipate and plan for have been used in the past three urban, agriculture, and forest lands are the future. Land use change models decades. Correlation between land use used to identify and quantify historic can also generate alternative land- change and pollution helps trends in sediment and nutrient loads scape predictions on the basis of dif- researchers establish positive or nega- in waters draining into the ferent land use policies and environ- tive trends that indicate whether pol- Chesapeake Bay. mental constraints. lution control strategies have been successful. With this information, pol- Geologists use data on land use These land use change models use icy makers, resource managers, and change to evaluate the availability of simple parameters including present the public can make appropriate building materials, such as sand, grav- urban extent, major transportation changes for the future. el, and cement. Geologists also use routes, topography, and protected data on existing hazards to correlate lands. Other factors, such as employ- Hydrologists can use Urban Dynamics with the UDR data to predict the ment opportunities, land prices, and data to evaluate new water sources for impacts of future natural disasters and the millions of personal decisions future urbanization and to analyze the potential damage they may cause. people make, are not considered in this modeling approach. The primary focus of the modeling effort is to account for physical controls on land Baltimore Baltimore use. Acknowledging the uncertainties of models, the USGS uses statistical methods to predict probabilities of urbanization. Washington D.C. Washington D.C. Impacts of Land Use Change

Urban Dynamics research in landscape characterization, urban growth models, and geographic understanding Baltimore Baltimore provides the data necessary for analyzing the impacts of population growth and land use change. This information can be used to analyze Washington D.C. Washington D.C. the causes of urban congestion, pollution, and loss of natural resources. Each of these impacts is linked to changes in the extent of urban, agricultural, and forested lands, and (or) transportation systems. Baltimore Baltimore Planners use Urban Dynamics data to evaluate environmental impacts, to delineate urban growth boundaries or service areas, to develop land use zon- Washington D.C. Washington D.C. ing plans, and to gauge future infrastructure requirements. Traffic congestion, a common malady of urbanization, is the result of urban growth, This series of maps shows more than 200 years of urban growth in and around the Washington, D.C. area. The background in each map is a shaded-relief image. The red areas represent urban extent for each time increases in population density, and period and the blue is Chesapeake Bay. Projections for 2025, made with a land use change model, show out-dated transportation infrastructure. likely areas of new urban growth in yellow (high probability) and in greens (light green is moderate probability; dark green is low probability). Baltimore Baltimore Baltimore Baltimore

Washington D.C. Washington D.C. Washington D.C. Washington D.C.

1850 1900 1953 1992

Baltimore Baltimore Baltimore Baltimore

Washington D.C. Washington D.C. Washington D.C. Washington D.C.

1850 1900 1953 1992

This series of maps compares changes in urban, agricultural, and forested lands in the Patuxent River watershed over the past 140 years. The top series shows the extent of urban areas (red) along with agriculture (gold), which was at its peak in the mid-to late-1800s. Since 1900, the amount of agricultural land has declined as urban and forested land (green) has increased.

Policy makers can then use these Study Sites Information damage or hazard projections to direct future development away from the UDR projects are underway in the For more information on the Urban most at-risk areas. metropolitan regions of Washington, Dynamics Research program, please D.C., Baltimore, Chicago, Milwaukee, contact Finally, biologists also use land use Portland, Vancouver, New York, William Acevedo change data to compile maps on habi- Philadelphia, San Francisco, and Las U.S. Geological Survey tats, species distribution, and land Vegas. Additional work is being done Ames Research Center MS 242-4 management. Predictions about future in the Detroit River corridor, Moffett Field, CA 94035 urbanization are critical to the protec- California's Central Valley, the Front Phone: 650-604-5299 tion of ecosystems and the sustain- Range corridor of Colorado, South Fax: 650-604-4680 ability of communities. Florida, and in the Middle Rio Grande Email: [email protected] Basin in New Mexico. Products Project descriptions, plans, and infor- Collaboration mation generated by the program are The UDR program provides temporal available at land use databases, analyses of land The UDR program is a joint activity use change, and landscape change between the USGS and the University http://edcwww2.cr.usgs.gov/urban. predictions. Databases for study sites of California, Santa Barbara. The contain digital maps of urban extent, Baltimore-Washington study was also For information on other USGS prod- transportation routes, water features, supported by the University of ucts and services, call 1-888-ASK- and other significant land uses com- Maryland, Baltimore County, NASA's USGS, use the ASK.USGS fax ser- patible for use in geographic informa- Mission to Planet Earth, U.S. Census vice, which is available 24-hours a tion systems (GIS). Digital animations Bureau, Library of Congress, day at 703-648-4888, or visit the gen- are available to help visualize the Smithsonian Institution, and Maryland eral interest publications web site on temporal patterns inherent in the data. Historic Trust. We are actively seek- mapping, geography, and related top- A land use change model and docu- ing the participation of organizations ics at mentation are also available. in new project areas as partners and http://mapping.usgs.gov/www/prod- Interpretive papers and maps based on clients. ucts/mappubs.html. the data and models are published in a variety of formats. Please visit the USGS home page at http://www.usgs.gov/.