Fulbright Proposal - Funded!

I propose to study the hydrologic and biogeochemical evolution of alpine critical zone environments of the Patagonia with Dr. Brian Reid, a biogeochemist at the Centro de Investigación en Ecosistemas de la Patagonia (CIEP) in Coyhaique, Chile. Dr. Reid conducts field studies on Patagonian volcanic ash soils and the ecosystem services they provide, but has not incorporated numerical modeling techniques. My computational skills can complement Dr. Reid’s work by providing novel insights into the underlying physical and chemical processes and predicting how these landscapes will evolve over time. Communities throughout the world rely on alpine watersheds for their water supply. Although there is strong evidence for global climate change, we do not yet understand how local water resources will be affected by shifting regional climate patterns. The Intergovernmental Panel on Climate Change (2013) warns that “changes in streamflow and water availability have been observed and projected to continue in the future in South America, affecting already vulnerable regions,” and the “risk of water supply shortages will increase owing to precipitation reductions and evapotranspiration increases in semi-arid regions, thus affecting water supply for cities, hydropower generation, and agriculture.” Alpine ecosystems are especially vulnerable due to short growing seasons, thin soils, sparse vegetation, melting glaciers, and thawing permafrost. In the Swiss Alps and Colorado Rockies, increased deposition of anthropogenic nitrogen and accelerated weathering processes that mobilize heavy metals have contributed to deterioration of downstream water quality. Impoverished areas are often disproportionately exposed to environmental contamination and resource scarcity, so it is urgent that we learn how climate change will affect water quantity and quality to allow such communities time to adapt and prepare.

The goal of the project is to apply hydrologic and biogeochemical models to alpine watersheds within the Chilean Patagonia to predict how climate change will affect local water yield and stream quality over the next century. These numerical models are based on universal physical principles that can be applied to any location on the Earth’s surface and produce reliable outputs for environmental variables such as soil moisture, groundwater storage, and groundwater chemistry on daily timescales. The first phase will involve collection of meteorological, soil, and water quantity and quality data. Dr. Reid has installed six meteorological stations in the area, and I plan to transport and install an additional station, as well as several handheld data acquisition tools. The first month will be spent in the field installing and troubleshooting data acquisition equipment to collect the suite of environmental data necessary for watershed modeling. During this time, I will work in parallel to model the dynamic evolution of volcanic ash soils, which are highly prone to erosion. Simplified modeling of the water storage properties of volcanic soils has been performed by Greco et al. (2013) but multi-layer models do not exist. In the second phase, I will process the data and customize the model to the Patagonia, verifying that the calculations match existing measurements. Data analysis and model calibration will involve one month spent in the home office at the CIEP adjusting input parameters to match observations and improving the models based on field insight from Dr. Reid and other researchers. Most model inputs are determined physically from meteorological data, but some must be obtained by fitting the model to the local watershed. When the hydrologic flow model has been refined, I will study the transport and reactions of nitrogen to investigate major differences in nutrient cycling in the northern and southern hemisphere. The final months will be spent driving the model with an ensemble of climate projections to predict how the timing, quantity, and quality of water resources will evolve in the next century. This process is exploratory and collaborative: I will work closely with other researchers at the CIEP and the Dirección General de Aguas (analogous to the US Geological Survey) who have already expressed interest in using these modeling tools for their own work. This collaboration may lead to probing the model further with additional research questions.

As a graduate student at the University of Colorado Boulder, I work with Dr. Harihar Rajaram and the Boulder Creek Critical Zone Observatory (BcCZO) developing computational simulations to determine how hill slope aspect (e.g. north- or south-facing) allows for the formation of seasonally-frozen ground, and controls hydrologic flow paths during snowmelt. The spatial distribution of frozen ground exerts a strong control on subsurface processes by reducing soil permeability, impeding infiltration, and inducing surface runoff (Walvoord and Kurylyk, 2016). Accordingly, degradation of frozen ground may allow for the propagation of weathering fronts into the deep subsurface, dissolving minerals from fresh bedrock. Gordon Gulch, a seasonally snow-covered montane catchment in the Colorado Rockies managed by the BcCZO, features two instrumented hill slopes with generally opposing aspects: the north-facing slope allows for the formation of a snowpack that persists throughout the winter season, while the inclination of the south-facing slope prevents snow accumulation. Soil temperature data from the north-facing slope shows that some water years allow for the formation of seasonally- frozen ground, while other years do not. To understand how interannual variability in the onset and depth of the snowpack on the north-facing slope controls the formation of seasonally- frozen ground, a surface energy balance model incorporating solar radiation and snowpack thermodynamics is coupled to PFLOTRAN-ICE, a thermo-hydrologic reactive flow and transport code (Karra et al., 2014). Extending these efforts to field sites in the Chilean Patagonia with varying aspects, soils, meteorology etc. will provide a robust experimental test of the models. In addition, the Aysén region’s unique location in a rural, mountainous, undeveloped area of the southern hemisphere offers a rare opportunity to isolate the influence of nitrogen deposition, which has been historically insignificant in southern Chile compared to the northern hemisphere (Galloway et al., 1994).

My background prepares me well for interdisciplinary research, allowing me to combine knowledge from hydrology, physics, chemistry, and biology. My past field experience includes identifying vegetation and classifying wetlands for two summers as a field technician throughout the state of Minnesota and leading field workshops at the Mountain Research Station in Colorado. I am proficient in Spanish and have experience living and studying in South America. I am a passionate educator and have experience collaborating on hydrologic modeling and engaging with the local community. As a University of Colorado Science Ambassador, I practice engaging non-scientific audiences and communicating technical ideas to the broader community. Through this program, I constructed a watershed demonstration that I use to share my research with younger students and bring my work to life. Dr. Pablo Mata, another researcher at the CIEP who works with glaciers and fjords, is interested in learning contemporary hydrologic modeling. Sharing these powerful predictive tools that are free and open-source with Chilean students and researchers will allow my work to continue following the travel period and produce a significant long-term impact in the region. In Coyhaique and Puerto Aysén, I will organize outreach events to listen to the experiences of community members, landowners, water utilities, and other stakeholders, as well as share the model predictions regarding water availability.

I hope to undertake this project in Chile in order to expand upon my research in Colorado and validate my graduate thesis by working closely with Dr. Reid and other researchers at the CIEP and engaging with the Aysén community. Comparing and contrasting sites in the Chilean Patagonia with the Colorado Rockies will produce deep insights into the fundamental physical processes that drive mountain watersheds, the regional consequences of global climate change, and the effects of nitrogen deposition on alpine ecosystems. These trends are widely documented in studies throughout the Swiss Alps and Colorado Rockies, but not in the Patagonia. In addition, I hope to maintain my Spanish fluency and build relationships in Latin America at large, a region where I plan to offer my skills, insight, and service for the rest of my career. During my brief time in Venezuela, I developed a profound appreciation and respect for the cultures of Latin America, and feel that I have much to learn from and contribute to these communities.

Timeline:

March, 2018	Arrive Coyhaique, Chile
April, 2018	Install and troubleshoot data acquisition equipment
May, 2018	Process and analyze meteorological data
June, 2018	Calibrate flow model
July, 2018	Calibrate nutrient transport and reaction model
August, 2018	Drive model with an ensemble of climate projections
September, 2018	Present results, facilitate community outreach events
October, 2018	Collaborate with CIEP researchers
November, 2018	Depart Coyhaique, Chile

References:
Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia,
V. Bex and P.M. Midgley [Eds.], Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
R. Greco, L. Comegna, E. Damiano, A. Guida, L. Olivares, and L. Picarelli, “Hydrological modelling of a slope covered with shallow pyroclastic deposits from field monitoring data,” Hydrol. Earth Syst. Sci., vol. 17, no. 10, pp. 4001–4013, Oct. 2013.
M. A. Walvoord and B. L. Kurylyk, “Hydrologic Impacts of Thawing Permafrost—A Review,” Vadose Zone Journal, vol. 15, no. 6, Jun. 2016.
S. Karra, S. L. Painter, and P. C. Lichtner, “Three-phase numerical model for subsurface hydrology in permafrost-affected regions (PFLOTRAN-ICE v1.0),” The Cryosphere, vol. 8, no. 5, pp. 1935–1950, Oct. 2014.
J. N. Galloway, H. Levy II, and P. S. Kasibhatla, “Year 2020: consequences of population growth and development on deposition of oxidized nitrogen,” Ambio, vol. 23, no. 2, pp. 120-123, Mar. 1994.