Santa Clara University

Iris Stewart-Frey

Associate Professor, Department Chair

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.