Santa Clara University

Environmental Studies - Iris Stewart-Frey

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IStewartFrey

Iris Stewart-Frey

Assistant Professor
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Office: Montgomery House, 874 Lafayette Street
Phone: (408) 551-7186
Email: istewartfrey@scu.edu

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Ph.D., Stanford University

bullet-leaf2 Curriculum Vitae

Teaching and Research Vision

I believe that learning is an active process. In my classes I encourage students to become active participants in the debate over past current and future environmental issues through both the understanding of the underlying physical processes, as well as their societal, political, legal, and spiritual components. Particular emphasis is given to the respectful communication of different findings and viewpoints to diverse audiences. My teaching therefore stresses discussions, research projects, presentations, hands-on learning, case studies, and class participation by every student.

In the broadest sense, my research interests encompass environmental issues that affect the water cycle and water supply. I have worked on both shallow groundwater pollution issues and surface water processes that are related to climate variability and climate change. Within this context, I have developed a type transfer function model (TTF) to assess pesticide leaching to groundwater at the regional scale. I have then used this model with in a GIS (Geographical Information Systems) framework to estimate Atrazine (a common herbicide) concentrations that would result at the water table from routine farming operations in the San Joaquin Valley in California. More recently I have worked on assessing streamflow timing changes across western North America. My collaborators and I have documented that streamflow timing for snowmelt dominated streams has changed toward an earlier spring over the past several decades and for an area much larger than previously recognized. These changes could have serious implications for the water supply of the dry southwestern regions. For another study, we used the relationships between past streamflow and climate to assess the impact of a warming climate on streamflow timing under a business-as-usual climate change scenario for the 21st century. My current work is focused on the physical processes and characteristics of watersheds which are particularly sensitive to climate change.


Courses Taught

ENVS 13: Soil, Air & Water
ENVS 20: The Water Wars of California L&L 
ENVS 115: Intro to GIS in Environmental Science L&L

Representative Publications


bullet-leaf2   Peterson DH, Stewart IT, Murphy F. 2008. Principal hydrologic responses to climatic and geologic variability in the Sierra Nevada, California. Estuary and Watershed Science, Vol.6, Issue 1 (February 2008), Article 1113.   
bullet-leaf2 Stewart IT, 2008. Changes in snowpack and snowmelt runoff for key mountain regions. Hydrologic Processes 22:in press  
bullet-leaf2 Cayan, D.R., M.D. Dettinger, I.T. Stewart, and N. Knowles, 2005, Recent changes toward earlier springs – Early sings of climate warming in western North America: Watershed Management Council Newsletter, Spring 2005, 13 p
bullet-leaf2 Peterson, D. H., R. Smith, I.T. Stewart, N. Knowles, C. Soulard, and S. Hager, 2005. Snowmelt discharge characteristics, Sierra Nevada, California, USGS Scientific Investigations Report 2005-5056, http://pubs.water.usgs.gov/sir2005-5056/
bullet-leaf2 Peterson, D.H., J.D. Lundquist, I.T. Stewart, N. Knowles, M. Solomon, and S.W. Hager, 2005: Sierra Nevada Hydroclimatology: An experimental prediction of maximum daily snow discharge in 2005, 16 p., http://meteora.ucsda.edu/cap.
bullet-leaf2 Stewart, I.T., D.R. Cayan, and M.D. Dettinger, 2005. Changes towards earlier streamflow timing across western North America, J. Climate,18, 1136-1155.
bullet-leaf2 Stewart, I.T., and K. Loague, 2004. Assessing groundwater vulnerability in the San Joaquin Valley (CA) with the type transfer function model, J. Environm. Qual., 33:1487-1498.
bullet-leaf2 Stewart, I.T., D.R. Cayan, and M.D. Dettinger, 2004. Changes in snowmelt runoff timing in western North America under a ‘Business as Usual’ climate change scenario, Climatic Change, 62:217-232.
bullet-leaf2 Stewart, I.T., and K. Loague, 2003. Development of type transfer functions for regional-scale non-point-source groundwater vulnerability assessments, Water Resour. Res., 39(12):1359.
bullet-leaf2 Stewart, I.T., and K. Loague, 1999. A type transfer function approach for regional-scale pesticide leaching assessments. J. Environ. Qual. 28:378-387.
bullet-leaf2 Loague, K., R.H. Abrams, S.N. Davis, A. Nguyen, and I.T. Stewart, 1998. A case study simulation of DBCP groundwater contamination in Fresno County, California. 2. Transport in the saturated subsurface. J. Contam. Hydrol. 29:137-163.