Emerging consequences of regional-scale aquifer depletion: data-driven and numerical models of well failure, basin salinization, and contaminant transport

Jun 9, 2020 3:00 PM — Jun 1, 2020 4:30 PM
PhD exit seminar
UC Davis
Davis, CA


Over the past century, extensive groundwater extraction has become cornerstone to global food production and personal water security. Estimates suggest that groundwater contributes a portion of the drinking water supply for at least 50% of the global population and accounts for 43% of all water used for irrigation. In California, groundwater supplies a portion of the drinking water supply for around 85% of residents, and nearly half of annual irrigation water. Moreover, an estimated 1.5 million households rely entirely on groundwater for basic needs via shallow, private domestic wells. Climate change, drought, and unsustainable aquifer depletion threaten the long-term sustainability of groundwater resources in California and worldwide, and models are needed to address emerging challenges. Using California’s Central Valley as a case study, three frontiers in water resources research are presented. (1) A data-driven model forecasts the spatial distribution of well failures (e.g., when a well runs dry) under future drought and groundwater management regimes in the Central Valley. (2) Simulations of groundwater flow and contaminant transport in the Tulare Basin show that groundwater pumping may convert an aquifer system into a closed basin that salinizes over decadal to century-long timescales. (3) Detailed 3D physical simulations of groundwater flow and nonpoint source contaminant transport in a highly heterogeneous aquifer-aquitard system demonstrate that the direction and magnitude of hydraulic gradients can modulate anomalous (non-Fickian) transport, with important implications for the development of upscaled regional-scale transport models.

Video Recording


First, I’d like to thank my mentors, advisors, academic coordinators, qualifying exam and dissertation committee members, labmates, and postdocs for teaching me so much and guiding me through the maze.

In particular, I want to acknowledge my major professor, Dr. Graham Fogg. For the past 5 years, I’ve been fortunate to receive Graham’s mentorship, patience, and humor. Graham gave me the freedom to make mistakes, to learn how to think independently, and to develop scientific curiosity.

I couldn't have made it without the support of the brilliant, thoughtful, and hard-working students in the hydrologic sciences graduate group that I took classes with, learned from, and grew with.

And I’m so grateful for the housemates and friends that make Davis feel like home, and that have kept me sane.

My family has believed in me every step of the way and encouraged me to pursue graduate education in moments of doubt, and I'm very thankful for them.

And I couldn’t have done this without my partner, the recent Dr. Marisa Donnelly. Throughout grad school, Marisa has been my best friend, my rock, and my family.

Rich Pauloo, PhD
Hydrologist and data scientist

My interests include hydrogeology, data science and web technologies, 3D groundwater flow and contaminant transport simulation, building simple solutions to complex problems, and expedition behavior.