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.

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)

The goal of the USGS Land Change Science (LCS) Program, formerly Geographic Analysis and Monitoring (GAM), 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 LCS 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 LCS 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 LCS 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.