USGS - science for a changing world

Geographic Analysis and Monitoring Program

Miami, FL - 1913 and 1997
These two photographs of the same location in Miami, taken in 1913 and 1997, demonstrate how dramatically urban expansion can alter the landscape, ecosystems, and the human environment over time. (Photos courtesy of Historical Museum of Southern Florida)

A Changing Planet

The surface of the Earth is changing rapidly, at local, regional, national, and global scales, with significant repercussions for people, the economy, and the environment. Some changes have natural causes, such as wildland fires or hurricanes, while other changes on the land, such as resource extraction, agricultural practices, and urban growth, are human-induced processes. There are other types of changes that are a combination of natural and human-induced factors; landslides and floods, for example, are fundamentally natural processes that are often intensified or accelerated by human land use practices. Whatever their cause, land-surface changes can have profound environmental and economic impacts.

The goal of the USGS Geographic Analysis and Monitoring (GAM) Program is to contribute to an understanding of the changes occurring and the consequences of these changes. It assesses the Earth's land cover at a range of spatial and temporal scales to better understand the causes and consequences of land cover change.

Innovative applications of GAM research encompass many fields, including climatic and hydrologic variability, biogeochemical cycling, ecosystem health, natural hazards analyses (including disaster prediction, mitigation, and response), and wildfire science. These applications provide a basis for resource managers and the public to understand the dynamic nature of our landscape and to anticipate the consequences of the interplay between natural processes and human actions.

The GAM Program is responsible for two national-scale projects: the National Land Cover Database (NLCD) and the Land Cover Status and Trends Reports. These long-term compilations of land cover conditions provide the foundation of USGS land-surface monitoring efforts, as well as those of numerous governmental and nongovernmental organizations. The results of these projects are necessary components of any regional or national environmental assessments.

Analytical approaches to the geographic relationship of natural hazards and society enable GAM researchers to develop methods and processes, such as decision-support systems and economic models that can facilitate the use of USGS science in public policy. By understanding the vulnerability and resilience of human and environmental systems in the context of place, geographic science can link assessments of potential hazards with the development of risk-reduction measures.

Featured Science Erosion Doubles Along Part of Alaska's Arctic Coast: Cultural and Historical Sites Lost

Coastal erosion has more than doubled in Alaska - up to 45 feet per year - in a 5-year period between 2002 and 2007 along a 40-mile stretch of the Beaufort Sea.

The U.S. Geological Survey-led study reveals that average annual erosion rates along this part of the Beaufort Sea climbed from historical levels of about 20 feet per year between the mid-1950s and late-1970s, to 28 feet per year between the late-1970s and early 2000s, to a rate of 45 feet per year between 2002 and 2007. The study was published in the current issue of Geophysical Research Letters, a publication of the American Geophysical Union.

USGS scientist and lead author Benjamin Jones cautioned that it is possible that the recent patterns documented in their study may represent a short-term episode of enhanced erosion. However, they may well represent the future pattern of coastline erosion in the Arctic. "Erosion of coastlines is a natural process, and this segment of coastline has historically eroded at some of the highest rates in the circum-Arctic, so the changes occurring on this open-ocean coast might not be occurring in other Arctic coastal settings," said Jones.

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GAM Fact Sheet
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