Dr. Sarah Null

Aquatic Habitat, Climate, and Water Analysis (ACWA) Lab


Water Resources Systems Modeling

SE Null. CAREER: Robust aquatic habitat representation for water resources decision-making. National Science Foundation (CAREER). ($510,095). Environmental Sustainability Program, Chemical, Bioengineering, Environmental, and Transport Systems (CBET) Division, Engineering Directorate. 2017 - 2022. ($510, 095).

The goal of this research is to represent aquatic habitat with multiple environmental attributes to quantify aquatic habitat in water resources systems modeling for robust decision-making. Environmental objectives are difficult to monetize, so are typically represented as constraints that remove them from decision-making, or functions of streamflow that do not correlate with organisms. Yet, simplicity and generalizable concepts that highlight fundamental water insights and develop the science of environmental objectives in water resources systems modeling are needed directions for the future. Thus, an essential dilemma of sustainable engineering is building models that are sufficiently realistic and acceptably general to make better decisions. Large spatial scale environmental data (streamflow, water quality, channel form, bioenergetics, etc.) makes it possible to integrate multiple habitat variables and validate them with organism presence to quantify concessions between accuracy and generality. Robust decision-making analytics weigh uncertain habitat representation ensembles in water resources systems models to identify stable decision-making when decisions are not easily reversible, such as for dam removal or construction. This supports long-term research and education goals of enhancing aquatic ecosystems while maintaining water resources benefits for people. Integrated research and education activities are to: 1) test the accuracy and generality of large spatial scale environmental data to represent aquatic habitat with varying levels of complexity, 2) quantify the robustness of aquatic habitat and hydro-economic tradeoffs in water resources systems models with uncertainty, and 3) expand public science literacy for water resources decision-making by integrating science with art.

Brothers, S, P Budy, SE Null, C Morrisett, R Van Kirk. Hydrological and Ecological Assessment of the Henry's Fork River and Island Park Reservoir to Support Multi-Stakeholder Management. 2018 - 2022.

In southeastern Idaho’s Henry’s Fork watershed, we’re identifying water management strategies to maintain water supply and aquatic habitat. Project objectives are to: (1) characterize streamflow-habitat relationships, (2) quantify groundwater contributions to the lower Henry’s Fork, (3) optimize reservoir delivery and managed aquifer recharge to meet competing water supply and instream flow objectives, and (4) investigate the adaptive capacity of Teton Valley agricultural producers to adopt farming practices that reduce irrigation needs. These objectives will guide an environmental flow recommendation for the lower Henry’s Fork.


ZS Hogan, S Chandra, SE Null, P Weisberg, C Jerde, . Wonders of the Mekong: A foundation for sustainable development and resilience. USAID. Sub-contract through University of Nevada, Reno (Project PI: Z Hogan). $4,724,544 ($77,720).

Crowl, TA, MA Baker, JR Ehleringer, D Jackson-Smith, DE Pataki. iUTAH-innovative Urban Transitions and Aridregion Hydro-sustainability. National Science Foundation (EPSCoR Track 1). $20,000,000 ($254,342).

I am co-lead of Coupled Human-Natural Systems research area (with Court Strong).

Although water systems are complex, a need exists for a generalized representation of these systems to identify important components and linkages to guide scientific inquiry and aid water management. We developed an integrated Structure-Actor-Water framework (iSAW) to facilitate the understanding of and transitions to sustainable water systems.

We are also using dual optimization to maximize stream habitat connectivity and water supply reliability by prioritizing barrier removal for migratory Bonneville cutthroat trout in Utah’s Weber River.

Hydroclimate Effects on Water Resources for People and Ecosystems

Budy, P, J Jin, SE Null. Collaborative Research: An exploration of the direct and indirect effects of climatic warming on arctic lake ecosystems. National Science Foundation (Arctic Research Opportunities). $658,109 ($85,800).

SE Null. Impacts of riparian restoration and climate change on stream temperatures in Meadow Creek. US Forest Service. 2015-2020, ($46,999).

Coordinated Management of Environmental Water Quantity and Quality

Dupont, RR, JE McLean, RC Peralta, SE Null, D Jackson-Smith. Assessment of stormwater harvesting via managed aquifer recharge to develop new water supplies in the arid west: the Salt Lake Valley example. EPA-STAR (EPA-G2014-STAR-F1). $750,000 ($173,736).

SE Null. Watershed Restoration Initiative Monitoring and Analysis. Utah Division of Wildlife Resources. 2015-2019. $91,841 ($80,524).

This research develops reach- and watershed-scale systems models to rank and prioritize river restoration alternatives. Research includes field data collection, hydrologic/water quality modeling, and systems optimization modeling to highlight restoration alternatives that best enhance water quantity and quality given project costs as constraints.

SE Null, S Chandra, D Sada, K Acharya. Evaluating and developing a habitat based model for trout that includes temperature, flow, and food production. National Fish and Wildlife Foundation. 2013-2016. $616,777 ($258,669). Part of the Walker Basin Project, Phase III led by Mike Collopy, $4,849,934.

Graduate Student Training

Huntly, N, P Belmont, C Flint, D Rosenberg, S Wang, L Gordillo, P Howe, J Lutz, SE Null, D Feldon. NRT: Graduate Climate Adaptation Research that Enhances Education and Responsiveness of science at the management-policy interface (Grad-CAREER). National Science Foundation (Research Traineeship Program). 2016 - 2021. $2,952,344 ($44,000).