Dr. Ruth DeFries

 
Education

Ph.D. (1980)   Department of Geography and Environmental Engineering
Johns Hopkins University, Baltimore, MD

B.A., summa cum laude (1976)
Washington University, St. Louis, MO (major in earth science)

Research Interests

• relationships between human activities, the land surface, and the biophysical and biogeochemical processes that regulate the Earth's habitability
• remote sensing of land cover change at regional and global scales to assess the consequences for ecosystem services

Ruth DeFries is an associate professor at the University of Maryland, College Park with joint appointments in the Department of Geography and the Earth System Science Interdisciplinary Center.    Her research investigates the relationships between human activities, the land surface, and the biophysical and biogeochemical processes that regulate the Earth's habitability.  She is interested in observing land cover and land use change at regional and global scales with remotely sensed data and exploring the implications for ecological services such as climate regulation, the carbon cycle, and biodiversity.  Dr. DeFries obtained a Ph.D. in 1980 from the Department of Geography and Environmental Engineering at Johns Hopkins University and a Bachelor's degree in 1976 from Washington University with a major in earth science.  Previously, Dr. DeFries worked at the National Research Council with the Committee on Global Change and taught at the Indian Institute of Technology in Bombay.  She is a fellow of the Aldo Leopold Leadership Program.

Research Projects

• A Global Network for Assessing Biogeochemical & Biophysical Consequences of Land Cover Disturbance
• Effects of Anthropogenic Land Cover Change on Climate
• Linking Top-Down and Bottom-Up Approaches to Quantifying Terrestrial Sources and Sinks of Carbon Using Satellite, Atmospheric, Ecosystem, and Historical Data
• Machine Learning to Improve Land Cover Classification from Multisensor and Multitemporal Data
• Towards Methodologies for Global Monitoring of Forest Cover Characteristics with Coarse Resolution Data

Representative Publications

DeFries, R., Bounoua, L. and Collatz, G.J., (2002, in press)

Human Modification of the Landscape and Surface Climate in the Next Fifty Years
Global Change Biology

DeFries, R., (2002, in press)

Past and Future Sensitivity of Primary Production to Human Modification of the Landscape.
Geophysical Research Letters

Bounoua, L., DeFries, R., Collatz, G.J., Sellers, P. and Khan, H., (2002)

Effects of land cover conversion on surface climate
Climatic Change, 52: 29-64.

DeFries, R. and Chan, J., (2000)

Multiple criteria for evaluating machine learning algorithms for land cover classification from satellite data.
Remote Sensing of Environment, 74: 503-515.

DeFries, R. Hansen, M., Townshend, J.R.G., Janetos, A.C., and Loveland, T.R. (2000)

A new global 1km data set of percent tree cover derived from remote sensing.
Global Change Biology, 6: 247-254.

DeFries, R., Field, C., Fung, I., Collatz, G. and Bounoua, L., 1999

Combining satellite data and biogeochemical models to estimate global effects of human-induced land cover change on carbon emissions and primary productivity
Global Biogeochemical Cycles, 13(3): 803-815.