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Department of Environmental Studies and Sciences

Iris Stewart-Frey

Iris Stewart-Frey

Professor, Environmental Studies Institute

Curriculum Vitae (CV)

Ph.D. in Hydrology, Stanford University
B.S. in Geology and Geophysics, University of Hawai'i

Professor Stewart-Frey teaches courses in water resources, water security, spatial analysis, community-based research, and earth systems.

Her research studies the impact of climate variability and change on water resources using models, and spatial & statistical analysis. She also uses a community-based approach to connect science findings to issues of justice in the distribution of environmental benefits and burdens. Professor Stewart-Frey is interested in interdisciplinary research and has collaborated with scholars from the fields of engineering, geography, ecology, and economics. Her research seeks to explain (i) recent and future impacts of climate warming on water resources, stream flows and temperatures, (ii) the impact of climate change across Central America and determinants for food and water security in the region, (iii) the role of climate, agriculture, laws, and infrastructure on water justice in Northern California, and (iv) the unequal distribution of environmental benefits and burdens in Silicon Valley with a focus on green spaces and roadway emissions. Examples of her recent work can be found here:  Climate Change Impacts Central America | Water Equity | Environmental Justice | Food and Water Security | Urban Stream Temperatures

Professor Stewart-Frey has published articles in a number of peer-reviewed journals, including the International Journal of Climatology, Journal of Hydrology, Journal of Climate, Water Resources Research, and World Development, and has been the PI/co-PI on US EPA and National Science Foundation grants. She has served as chair of the department of Environmental Studies and Sciences, and on the university’s Faculty Affairs Committee. She is a former Clare Boothe Luce scholar, a member of the Environmental Justice and the Common Good Initiative at SCU, a co-organizer of the Northern California Network for Community-Academic Partnerships for Environmental Justice Teaching and Research, a Science Advisor to the Tuolumne River Trust, and an Associate Editor for the Journal of the American Water Resources Association. She frequently mentors undergraduate student researchers, and has co-mentored two graduate students and two postdoctoral researchers.



ENVS 20: The Water Wars of California

ENVS 23: Earth Systems

ENVS 101: Capstone

ENVS 115: L&L GIS in Environmental Science

ENVS 116: Introduction to GIS

ENVS 117: Intermediate GIS

ENVS 160: L&L Water Resources

ENVS 161: Water Security (Advanced Writing)


Selected Publications

*denoted undergraduate student co-authors

Stewart IT, Maurer EP, Stahl K, *Joseph K, 2021. Recent evidence for warmer and drier growing seasons in climate sensitive regions of Central America from multiple global data sets. International Journal of Climatology. 2021 Aug.

Bacon CM, Sundstrom WA, Stewart IT, Maurer E, Kelley LC, 2021. Towards smallholder food and water security: Climate variability in the context of multiple livelihood hazards in Nicaragua. World Development. 2021 Jul 1;143:105468.

Stewart IT, *Rogers J, *Graham A, 2020. Water security under severe drought and climate change: Disparate impacts of the recent severe drought on environmental flows and water supplies in Central California. Journal of Hydrology X. 2020 Apr 1;7:100054.

Stewart IT, *Engh MK, *Parchem CP, 2020. Effect of Climate Warming and Drought on Urban Stream Temperatures in a Semiarid, Seasonal System. JAWRA Journal of the American Water Resources Association. 2020 Aug;56(4):551-67.

Stewart IT, Ficklin, DL, *Carrillo CA, *McIntosh R., 2015. 21st century increases in the likelihood of extreme hydrologic conditions for the mountainous basins of the Southwestern United States. Journal of Hydrology, 529, 340-353.

Stewart IT, Bacon CM, *Burke WD, 2014. The uneven distribution of environmental burdens and benefits in Silicon Valley’s backyard, Applied Geography 55, 1-12

Ficklin, DL, Stewart IT, Maurer EP, 2013. Effects of climate change on water quality in the Sierra Nevada mountain range in California. Wat. Resour. Res. 49:2765-2782, doi:10.1002/wrcr.20248

Ficklin DL, Luo Y, Stewart IT, Maurer EP, 2012. Development and application of a hydroclimatological stream temperature model within SWAT. Water Resources Research. Vol 48, W01511, doi:10.1029/2011WR011256.

*Fritze H, Stewart IT, Pebesma EJ, 2011. Shifts in Western North American snowmelt runoff regimes for the recent warm decades. . Hydromet. doi: 10.1175/2011JHM1360.1

Stewart IT, 2009. Changes in snowpack and snowmelt runoff for key mountain regions. Hydrologic Processes 23:78-94.

Stewart IT, Cayan DR, Dettinger MD, 2005. Changes towards earlier streamflow timing across western North America, J. Climate,18:1136-1155.

Stewart IT, Loague K, 2003. Development of type transfer functions for regional-scale non-point-source groundwater vulnerability assessments, Water Resour. Res., 39(12):1359.


In the News

January 4, 2024

Iris Stewart-Frey and Jake Dialesandro's research comparing shade coverage in wealthier versus disadvantaged communities in the city of Fresno in California’s Central Valley was noted in AGU's Eos.

May 17, 2021

Iris Stewart-Frey lead a study on the allocation of water from the Tuolumne River during extreme droughts.