Sheila Murphy
Biography
Sheila Murphy is a hydrologist who focuses on how disturbances (such as wildfire, floods, hurricanes, land use change) alter watershed response, water quality, and water quantity. Her recent research has evaluated the effects of wildfire on water quality in the western U.S., and the hydrologic and geochemical responses to geology, land cover change, and hurricanes in a tropical forest in Puerto Rico.
Data Releases
Murphy, S. F., McCleskey, R. B., & Writer, J. H., 2018, Water chemistry data for Fourmile Creek Watershed, 2010-2015. U.S. Geological Survey database, https://doi.org/10.5066/F7Z60N8T
Murphy, S.F., Stallard, R.F., Scholl, M.A., González, G., and Torres-Sánchez, A.J., 2017, Geospatial data for Luquillo Mountains, Puerto Rico—Mean annual precipitation, elevation, watershed outlines, and rain gage locations: U.S. Geological Survey data release, https://doi.org/10.5066/F74F1PM2
Science and Products
Connections between Forested and Urban Landscapes and Implications for Water Supply
Interactions between forested and urban landscapes can lead to reciprocal effects that have substantial impacts on water supply and ecology. Air pollution from urban and forested landscapes can be deposited on adjacent forests, while forest disturbance, such as wildfires and floods, can remobilize those contaminants. Additionally, pollutants from legacy land use (e.g., mining) can also be...
Inorganic nitrogen wet deposition gradients in the Denver-Boulder metropolitan area and Colorado Front Range – Preliminary implications for Rocky Mountain National Park and interpolated deposition maps
For the first time in the 40-year history of the National Atmospheric Deposition Program / National Trends Network (NADP/NTN), a unique urban-to-rural transect of wet deposition monitoring stations were operated as part of the NTN in 2017 to quantify reactive inorganic nitrogen wet deposition for adjacent urban and rural, montane regions. The...
Wetherbee, Gregory A.; Benedict, Katherine ; Murphy, Sheila F.; Elliott, Emily Fire, flood, and drought: Extreme climate events alter flow paths and stream chemistry
Extreme climate events—such as hurricanes, droughts, extreme precipitation, and wildfires—have the potential to alter watershed processes and stream response. Yet due to the destructive and hazardous nature and unpredictability of such events, capturing their hydrochemical signal is challenging. A 5‐year postwildfire study of stream chemistry in...
Murphy, Sheila F.; McCleskey, R. Blaine; Martin, Deborah A.; Writer, Jeffrey H.; Ebel, Brian A. Before the storm: Antecedent conditions as regulators of hydrologic and biogeochemical response to extreme climate events
While the influence of antecedent conditions on watershed function is widely recognized under typical hydrologic regimes, gaps remain in the context of extreme climate events (ECEs). ECEs are those events that far exceed seasonal norms of intensity, duration, or impact upon the physical environment or ecosystem. In this synthesis, we discuss the...
McMillan, Sara K.; Wilson, Henry F.; Tague, Christina L.; Hanes, Daniel M.; Inamdar, Shreeram; Karwan, Diana L.; Loecke, Terry; Morrison, Jonathan; Murphy, Sheila F.; Vidon, Philippe Anthropocene landscape change and the legacy of nineteenth- and twentieth-century mining in the Fourmile Catchment, Colorado Front Range
Human impacts on earth surface processes and materials are fundamental to understanding the proposed Anthropocene epoch. This study examines the magnitude, distribution, and long-term context of nineteenth- and twentieth-century mining in the Fourmile Creek catchment, Colorado, coupling airborne LiDAR topographic analysis with historical documents...
Dethier, David P.; Ouimet, William B.; Murphy, Sheila F.; Kotikian, Maneh; Wicherski, Will; Samuels, Rachel M. A method for quantifying cloud immersion in a tropical mountain forest using time-lapse photography
Quantifying the frequency, duration, and elevation range of fog or cloud immersion is essential to estimate cloud water deposition in water budgets and to understand the ecohydrology of cloud forests. The goal of this study was to develop a low-cost and high spatial-coverage method to detect occurrence of cloud immersion within a mountain cloud...
Bassiouni, Maoya; Scholl, Martha A.; Torres-Sanchez, Angel J.; Murphy, Sheila F. Reassessing rainfall in the Luquillo Mountains, Puerto Rico: Local and global ecohydrological implications
Mountains receive a greater proportion of precipitation than other environments, and thus make a disproportionate contribution to the world’s water supply. The Luquillo Mountains receive the highest rainfall on the island of Puerto Rico and serve as a critical source of water to surrounding communities. The area’s role as a long-term research site...
Murphy, Sheila F.; Stallard, Robert F.; Scholl, Martha A.; Gonzalez, Grizelle; Torres-Sanchez, Angel J. Critical zone properties control the fate of nitrogen during experimental rainfall in montane forests of the Colorado Front Range
Several decades of research in alpine ecosystems have demonstrated links among the critical zone, hydrologic response, and the fate of elevated atmospheric nitrogen (N) deposition. Less research has occurred in mid-elevation forests, which may be important for retaining atmospheric N deposition. To explore the fate of N in the montane zone, we...
Hinckley, Eve-Lyn S.; Ebel, Brian A.; Barnes, Rebecca T.; Murphy, Sheila F.; Anderson, Suzanne P. Water-quality response to a high-elevation wildfire in the Colorado Front Range
Water quality of the Big Thompson River in the Front Range of Colorado was studied for 2 years following a high-elevation wildfire that started in October 2012 and burned 15% of the watershed. A combination of fixed-interval sampling and continuous water-quality monitors was used to examine the timing and magnitude of water-quality changes...
Mast, Alisa; Murphy, Sheila F.; Clow, David W.; Penn, Colin A.; Sexstone, Graham A. The role of precipitation type, intensity, and spatial distribution in source water quality after wildfire
Storms following wildfires are known to impair drinking water supplies in the southwestern United States, yet our understanding of the role of precipitation in post-wildfire water quality is far from complete. We quantitatively assessed water-quality impacts of different hydrologic events in the Colorado Front Range and found that for a three-year...
Murphy, Sheila F.; Writer, Jeffrey H.; McCleskey, R. Blaine; Martin, Deborah A. Stable-isotope and solute-chemistry approaches to flow characterization in a forested tropical watershed, Luquillo Mountains, Puerto Rico
The prospect of changing climate has led to uncertainty about the resilience of forested mountain watersheds in the tropics. In watersheds where frequent, high rainfall provides ample runoff, we often lack understanding of how the system will respond under conditions of decreased rainfall or drought. Factors that govern water supply, such as...
Scholl, Martha A.; Shanley, James B.; Murphy, Sheila F.; Willenbring, Jane K; Occhi, Marcie; González, Grizelle Precipitation isotopes link regional climate patterns to water supply in a tropical mountain forest, eastern Puerto Rico
Like many mountainous areas in the tropics, watersheds in the Luquillo Mountains of eastern Puerto Rico have abundant rainfall and stream discharge and provide much of the water supply for the densely populated metropolitan areas nearby. Projected changes in regional temperature and atmospheric dynamics as a result of global warming suggest that...
Scholl, Martha A.; Murphy, Sheila F. A unified assessment of hydrological and biogeochemical responses in research watersheds in Eastern Puerto Rico using runoff-concentration relations
An examination of the relation between runoff rate, R, and concentration, C, of twelve major constituents in four small watersheds in eastern Puerto Rico demonstrates a consistent pattern of responses. For solutes that are not substantially bioactive (alkalinity, silica, calcium, magnesium, sodium, and chloride), the log(R)–log(C)...
Stallard, Robert F.; Murphy, Sheila F.