Scholars@Duke
Ryan Emanuel

Ryan Emanuel

Associate Professor of Hydrology
Environmental Sciences and Policy
ryan.emanuel@duke.edu
9 Circuit Dr., Durham, NC 27708

Selected Publications

Beyond environmental harm: Industry claims, lived experiences, and the impacts of gas extraction

Journal Article Energy Research and Social Science · September 1, 2024 The peer-reviewed literature presents overwhelming evidence that fossil fuel based energy infrastructure projects are responsible for lower residential property values, environmental destruction and pollution that decrease residents' quality of life. These ... Full text Cite

Standard metrics for characterizing episodic salinization in freshwater systems

Journal Article Limnology and Oceanography: Methods · September 1, 2024 Salinization threatens freshwater resources and freshwater-dependent wetlands in coastal areas worldwide. Many research efforts focus on gradual or chronic salinization, but the phenomenon is also episodic in nature, particularly in small streams and artif ... Full text Cite

Leaf Physiological Responses and Early Senescence Are Linked to Reflectance Spectra in Salt-Sensitive Coastal Tree Species

Journal Article Forests · September 1, 2024 Salt-sensitive trees in coastal wetlands are dying as forests transition to marsh and open water at a rapid pace. Forested wetlands are experiencing repeated saltwater exposure due to the frequency and severity of climatic events, sea-level rise, and human ... Full text Cite

Revisiting Vine Deloria's Support for Unrecognized Tribes in a Time of Environmental Crises

Chapter · April 16, 2024 Of Living Stone: Perspectives on Continuous Knowledge and the Work of Vine Deloria, Jr. is a collection of new essays on the legacy of Vine Deloria, Jr., one of the most influential thinkers of our time. ... Cite

On the Swamp Fighting for Indigenous Environmental Justice

Book · April 2, 2024 Addressing issues from the loss of wetlands to the arrival of gas pipelines, these stories connect the dots between historic patterns of Indigenous oppression and present-day efforts to promote environmental justice and Indigenous rights on ... ... Cite

Saltwater intrusion and sea level rise threatens U.S. rural coastal landscapes and communities

Journal Article Anthropocene · March 1, 2024 The United States (U.S.) coastal plain is subject to rising sea levels, land subsidence, more severe coastal storms, and more intense droughts. These changes lead to inputs of marine salts into freshwater-dependent coastal systems, creating saltwater intru ... Full text Cite

Location and Design of Flow Control Structures Differentially Influence Salinity Patterns in Small Artificial Drainage Systems

Journal Article Journal of Water Resources Planning and Management · June 1, 2023 Saltwater intrusion is a pervasive threat to coastal ecosystems. Common management strategies entail the installment of engineered flow control structures, though there is a dearth of work on their prevalence across the landscape and how different structur ... Full text Cite

Does shale gas development impact property values in Central Appalachia? A mixed methods critical exploration

Journal Article Extractive Industries and Society · June 1, 2023 Increased shale gas extraction through hydraulic fracturing and its distribution through shale gas pipelines have brought about innumerable socioeconomic consequences, both tangibly and intangibly. Evidence remains unclear on what are the impacts of shale ... Full text Cite

Riparian buffers increase future baseflow and reduce peakflows in a developing watershed.

Journal Article The Science of the total environment · March 2023 Land conversion and climate change are stressing freshwater resources. Riparian areas, streamside vegetation/forest land, are critical for regulating hydrologic processes and riparian buffers are used as adaptive management strategies for mitigating land c ... Full text Cite

Bifurcation: An Indigenous Perspective on Water Science and Water Justice

Chapter · 2023 Voices of Indigenuity collects the voices of the Indigenous Speaker Series and multigenerational Indigenous peoples to introduce best practices for traditional ecological knowledge (TEK). In this edited collection, presenters from the series, both within a ... Link to item Cite

Coastal Plain, North Carolina

Journal Article SOUTHERN CULTURES · 2023 Cite

Response of soil respiration to changes in soil temperature and water table level in drained and restored peatlands of the southeastern United States.

Journal Article Carbon balance and management · November 2022 BackgroundExtensive drainage of peatlands in the southeastern United States coastal plain for the purposes of agriculture and timber harvesting has led to large releases of soil carbon as carbon dioxide (CO2) due to enhanced peat decomp ... Full text Cite

Extreme Flooding and Nitrogen Dynamics of a Blackwater River

Journal Article Water Resources Research · December 1, 2021 Extreme floods, including those expected to become more frequent in a warming world, may impact nutrient metabolism in streams. However, flood impacts on spatial and temporal variability of nutrient dynamics on large rivers (e.g., fourth order and higher) ... Full text Cite

Values-Based Scenarios of Water Security: Rights to Water, Rights of Waters, and Commercial Water Rights

Journal Article BioScience · November 1, 2021 Although a wide body of scholarly research recognizes multiple kinds of values for water, water security assessments typically employ just some of them. In the present article, we integrate value scenarios into a planetary water security model to incorpora ... Full text Cite

Microbial Contamination in Environmental Waters of Rural and Agriculturally-Dominated Landscapes Following Hurricane Florence

Journal Article ACS ES and T Water · September 10, 2021 Hurricane Florence brought unprecedented rainfall and flooding to Eastern North Carolina in 2018. Extensive flooding had the potential to mobilize microbial contaminants from a variety of sources. Our study evaluated microbial contaminants in surface water ... Full text Cite

Soil Moisture Responses to Rainfall: Implications for Runoff Generation

Journal Article Water Resources Research · September 1, 2021 Soil moisture is a key control on runoff generation and biogeochemical processes on hillslopes. Precipitation events can evoke different soil moisture responses with depth through the soil profile, and responses can differ among landscape positions along a ... Full text Cite

Natural Gas Gathering and Transmission Pipelines and Social Vulnerability in the United States.

Journal Article GeoHealth · June 2021 Midstream oil and gas infrastructure comprises vast networks of gathering and transmission pipelines that connect upstream extraction to downstream consumption. In the United States (US), public policies and corporate decisions have prompted a wave of prop ... Full text Cite

Search for Campylobacter spp. Reveals High Prevalence and Pronounced Genetic Diversity of Arcobacter butzleri in Floodwater Samples Associated with Hurricane Florence in North Carolina, USA.

Journal Article Applied and environmental microbiology · October 2020 In September 2018, Hurricane Florence caused extreme flooding in eastern North Carolina, USA, a region highly dense in concentrated animal production, especially swine and poultry. In this study, floodwater samples (n = 96) were collected as promptl ... Full text Cite

Breaching barriers: The fight for indigenous participation in water governance

Journal Article Water (Switzerland) · August 1, 2020 Indigenous peoples worldwide face barriers to participation in water governance, which includes planning and permitting of infrastructure that may affect water in their territories. In the United States, the extent to which Indigenous voices are heard-let ... Full text Cite

Non-linear quickflow response as indicators of runoff generation mechanisms

Journal Article Hydrological Processes · June 30, 2020 Linking quickflow response to subsurface state can improve our understanding of runoff processes that drive emergent catchment behaviour. We investigated the formation of non-linear quickflows in three forested headwater catchments and also explored unsatu ... Full text Cite

Spatial and Temporal Patterns in Baseflow Recession in the Continental United States

Journal Article Water Resources Research · March 1, 2020 Baseflow is often treated according to a unique storage-discharge relationship. However, recent innovations in baseflow recession analysis have allowed novel findings regarding the variability of both the stability of baseflow and its nonlinearity (i.e., t ... Full text Cite

Applying Climate Change Risk Management Tools to Integrate Streamflow Projections and Social Vulnerability

Journal Article Ecosystems. · January 2020 Shifts in streamflow, due to future climate and land use change, may pose risks to nearby human communities. Projecting the spatial distribution and impacts of these risks requires consideration of biophysical and socioeconomic factors. Models like the Soi ... Full text Cite

Decadal-Scale Vegetation Change Driven by Salinity at Leading Edge of Rising Sea Level

Journal Article Ecosystems. · December 2019 As sea levels rise, low-lying coastal forests increasingly are subject to stressors such as inundation and saltwater exposure. At long timescales (for example, centuries), the extent of inundation and saltwater exposure will increase; however, on a decadal ... Full text Cite

Ecohydrology of Interannual Changes in Watershed Storage

Journal Article Water Resources Research · October 1, 2019 Watershed studies often rely on the assumption that interannual storage changes are negligible in the hydrologic balance of a watershed. The assumption can be useful and is sometimes necessary, but it is widely acknowledged as unrealistic. Identifying and ... Full text Cite

Linking residential saltwater intrusion risk perceptions to physical exposure of climate change impacts in rural coastal communities of North Carolina

Journal Article Natural Hazards · July 15, 2019 The salinization of freshwater-dependent coastal ecosystems precedes inundation by sea level rise. This type of saltwater intrusion places communities, ecosystems, and infrastructure at substantial risk. Risk perceptions of local residents are an indicator ... Full text Cite

Indigenous Symposium on Water Research, Education, and Engagement

Journal Article Eos · January 24, 2019 Water in the Native World: The Intersection of Hydrology and Indigenous Knowledge; Pablo, Montana, 1–4 August 2018 ... Full text Cite

Water in the Lumbee world: A river and its people in a time of change

Journal Article Environmental History · January 1, 2019 This article explores relationships between Lumbee people and the riverine landscapes of their home. I draw upon my lived experience as a Lumbee person and my training as an environmental scientist to evaluate the riverine environment of the Lumbee River a ... Full text Cite

The Relative Influence of Storm and Landscape Characteristics on Shallow Groundwater Responses in Forested Headwater Catchments

Journal Article Water Resources Research · December 1, 2018 Shallow groundwater responses to rainfall in forested headwaters can be highly variable, but their relative strengths of influences remain poorly understood. We investigated the roles of storms and landscape characteristics on short-term, shallow groundwat ... Full text Cite

Assessment of hydrologic vulnerability to urbanization and climate change in a rapidly changing watershed in the Southeast U.S.

Journal Article The Science of the total environment · December 2018 This study assessed the combined effects of increased urbanization and climate change on streamflow in the Yadkin-Pee Dee watershed (North Carolina, USA) and focused on the conversion from forest to urban land use, the primary land use transition occurring ... Full text Cite

Sea level rise impacts on rural coastal social-ecological systems and the implications for decision making

Journal Article Environmental Science and Policy · December 1, 2018 Many rural coastal regions are distinctly vulnerable to sea level rise because of their remoteness, isolation from central planning agencies, and poverty. To better plan for future sea level changes in these regions, an interdisciplinary approach to assess ... Full text Cite

Terra incognita: The unknown risks to environmental quality posed by the spatial distribution and abundance of concentrated animal feeding operations.

Journal Article The Science of the total environment · November 2018 Concentrated animal feeding operations (CAFOs) pose wide ranging environmental risks to many parts of the US and across the globe, but datasets for CAFO risk assessments are not readily available. Within the United States, some of the greatest concentratio ... Full text Cite

Understanding coastal wetland hydrology with a new regional scale process-based hydrologic mode

Journal Article Hydrological Processes · July 27, 2018 Coastal wetlands represent an ecotone between ocean and terrestrial ecosystems, providing important services, including flood mitigation, fresh water supply, erosion control, carbon sequestration, and wildlife habitat. The environmental setting of a wetlan ... Full text Cite

Climate Change in the Lumbee River Watershed and Potential Impacts on the Lumbee Tribe of North Carolina

Journal Article Journal of Contemporary Water Research & Education · April 2018 AbstractA growing body of research focuses on climate change and Indigenous peoples. However, relatively little of this work focuses on Native American tribes living in the Atlantic Coastal Plain of the United States. The L ... Full text Cite

Unexpected ecological advances made possible by long-term data: A Coweeta example

Journal Article Wiley Interdisciplinary Reviews: Water · March 1, 2018 In the 1970s, Forest Service and academic researchers clearcut the forest in Watershed 7 in the Coweeta Basin to observe how far the perturbation would move the ecosystem and how quickly the ecosystem would return to its predisturbance state. Our long-term ... Full text Cite

Evaluating the effects of land-use change and future climate change on vulnerability of coastal landscapes to saltwater intrusion

Journal Article Elementa · January 1, 2018 The exposure of freshwater-dependent coastal ecosystems to saltwater is a present-day impact of climate and land-use changes in many coastal regions, with the potential to harm freshwater and terrestrial biota, alter biogeochemical cycles and reduce agricu ... Full text Cite

Complex terrain influences ecosystem carbon responses to temperature and precipitation

Journal Article Global Biogeochemical Cycles · August 1, 2017 Terrestrial ecosystem responses to temperature and precipitation have major implications for the global carbon cycle. Case studies demonstrate that complex terrain, which accounts for more than 50% of Earth's land surface, can affect ecological processes a ... Full text Cite

Flawed environmental justice analyses.

Journal Article Science (New York, N.Y.) · July 2017 Full text Cite

How are streamflow responses to the El Nino Southern Oscillation affected by watershed characteristics?

Journal Article Water Resources Research · May 1, 2017 Understanding the factors that influence how global climate phenomena, such as the El-Nino Southern Oscillation (ENSO), affect streamflow behavior is an important area of research in the hydrologic sciences. While large-scale patterns in ENSO-streamflow re ... Full text Cite

The influence of watershed characteristics on spatial patterns of trends in annual scale streamflow variability in the continental U.S.

Journal Article Journal of Hydrology · September 1, 2016 As human activity and climate variability alter the movement of water through the environment the need to better understand hydrologic cycle responses to these changes has grown. A reasonable starting point for gaining such insight is studying changes in s ... Full text Cite

Hydro-Climatological Influences on Long-Term Dissolved Organic Carbon in a Mountain Stream of the Southeastern United States.

Journal Article Journal of environmental quality · July 2016 In the past decade, significant increases in surface water dissolved organic carbon (DOC) have been reported for large aquatic ecosystems of the Northern Hemisphere and have been attributed variously to global warming, altered hydrologic conditions, and at ... Full text Cite

Hydrologic Impacts of Municipal Wastewater Irrigation to a Temperate Forest Watershed.

Journal Article Journal of environmental quality · July 2016 Land application of municipal wastewater to managed forests is an important treatment and water reuse technology used globally, but the hydrological processes of these systems are not well characterized for temperate areas with annual rainfall of 1200 mm o ... Full text Cite

Variability in isotopic composition of base flow in two headwater streams of the southern Appalachians

Journal Article Water Resources Research · June 1, 2016 We investigated the influence of hillslope scale topographic characteristics and the relative position of hillslopes along streams (i.e., internal catchment structure) on the isotopic composition of base flow in first-order, forested headwater streams at C ... Full text Cite

Watershed memory at the Coweeta Hydrologic Laboratory: The effect of past precipitation and storage on hydrologic response

Journal Article Water Resources Research · March 1, 2016 The rainfall-runoff response of watersheds is affected by the legacy of past hydroclimatic conditions. We examined how variability in precipitation affected streamflow using 21 years of daily streamflow and precipitation data from five watersheds at the Co ... Full text Cite

Influence of basin characteristics on the effectiveness and downstream reach of interbasin water transfers: Displacing a problem

Journal Article Environmental Research Letters · December 8, 2015 Interbasin water transfers are globally important water management strategies, yet little is known about their role in the hydrologic cycle at regional and continental scales. Specifically, there is a dearth of centralized information on transfer locations ... Full text Cite

Landscape position influences microbial composition and function via redistribution of soil water across a watershed.

Journal Article Applied and environmental microbiology · December 2015 Subalpine forest ecosystems influence global carbon cycling. However, little is known about the compositions of their soil microbial communities and how these may vary with soil environmental conditions. The goal of this study was to characterize the soil ... Full text Cite

Land–atmosphere carbon and water flux relationships to vapor pressure deficit, soil moisture, and stream flow

Journal Article Agricultural and Forest Meteorology. · August 2015 Climatic change is exerting considerable influence on the hydrologic and biogeochemical cycles of snow- dominated montane forest ecosystems. Growing season drought stress is a common occurrence after snowmelt-derived soil water content (WC) and stream flow ... Full text Cite

Continental U.S. streamflow trends from 1940 to 2009 and their relationships with watershed spatial characteristics

Journal Article Water Resources Research · August 1, 2015 Changes in streamflow are an important area of ongoing research in the hydrologic sciences. To better understand spatial patterns in past changes in streamflow, we examined relationships between watershed-scale spatial characteristics and trends in streamf ... Full text Cite

The spatial and temporal evolution of contributing areas

Journal Article Water Resources Research · June 1, 2015 Predicting runoff source areas and how they change through time is a challenge in hydrology. Topographically induced lateral water redistribution and water removal through evapotranspiration lead to spatially and temporally variable patterns of watershed w ... Full text Cite

Landscape position and spatial patterns in the distribution of land use within the southern Appalachian Mountains

Journal Article Physical Geography · September 3, 2014 Understanding the forces that influence the distribution of land use and land-use change (LUC) is an essential step in developing effective strategies for managing these issues. We examined the influence of landscape position on spatial patterns in land-us ... Full text Cite

A simple framework to estimate distributed soil temperature from discrete air temperature measurements in data-scarce regions

Journal Article Journal of Geophysical Research Atmospheres · January 27, 2014 Soil temperature is a key control on belowground chemical and biological processes. Typically, models of soil temperature are developed and validated for large geographic regions. However, modeling frameworks intended for higher spatial resolutions (much f ... Full text Cite

Ecohydrological flow networks in the subsurface

Journal Article Ecohydrology · January 1, 2014 Preferential flow in hillslope systems through subsurface networks developed from a range of botanical, faunal and geophysical processes have been observed and inferred for decades and may provide a large component of the bulk transport of water and solute ... Full text Cite

Ecohydrology of an outbreak: Mountain pine beetle impacts trees in drier landscape positions first

Journal Article Ecohydrology · June 1, 2013 Vegetation pattern and landscape structure intersect to exert strong control over ecohydrological dynamics at the watershed scale. The hydrologic implications of vegetation disturbance (e.g. fire, disease) depend on the spatial pattern and form of environm ... Full text Open Access Cite

Complex terrain leads to bidirectional responses of soil respiration to inter-annual water availability

Journal Article Global Change Biology · February 1, 2012 Research on the terrestrial C balance focuses largely on measuring and predicting responses of ecosystem-scale production and respiration to changing temperatures and hydrologic regimes. However, landscape morphology can modify the availability of resource ... Full text Cite

Landscape structure and climate influences on hydrologic response

Journal Article Water Resources Research · December 26, 2011 Climate variability and catchment structure (topography, geology, vegetation) have a significant influence on the timing and quantity of water discharged from mountainous catchments. How these factors combine to influence runoff dynamics is poorly understo ... Full text Cite

On the spatial heterogeneity of net ecosystem productivity in complex landscapes

Journal Article Ecosphere · July 1, 2011 Micrometeorological flux towers provide spatially integrated estimates of net ecosystem production (NEP) of carbon over areas ranging from several hectares to several square kilometers, but they do so at the expense of spatially explicit information within ... Full text Cite

A watershed-scale assessment of a process soil CO2 production and efflux model

Journal Article Water Resources Research · June 10, 2011 Growing season soil CO2 efflux is known to vary laterally by as much as seven fold within small subalpine watersheds (<5 km2), and such degree of variability has been strongly related to the landscape-imposed redistribution of soil water. Current empirical ... Full text Cite

Training a new scientist to meet the challenges of a changing environment

Journal Article Eos · May 30, 2011 The transboundary nature of global environmental change demands collaborative, multiscale, interdisciplinary research [U.S. National Academy of Sciences, 2005]. This requires "a new kind of scientist" [Schmidt and Moyer, 2008]; collaborators must develop b ... Full text Cite

Spatial and temporal controls on watershed ecohydrology in the northern Rocky Mountains

Journal Article Water Resources Research · December 10, 2010 Vegetation water stress plays an important role in the movement of water through the soil-plant-atmosphere continuum. However, the effects of water stress on evapotranspiration (ET) and other hydrological processes at the watershed scale remain poorly unde ... Full text Cite

Effect of interannual climate oscillations on rates of submarine groundwater discharge

Journal Article Water Resources Research · May 1, 2010 Submarine groundwater discharge (SGD) is an important component of the coastal hydrologic cycle, affecting mixing and biogeochemistry in the nearshore environment. El Niño-Southern Oscillation (ENSO) influences rates of precipitation and groundwater rechar ... Full text Cite

Effect of interannual and interdecadal climate oscillations on groundwater in North Carolina

Journal Article Geophysical Research Letters · December 16, 2008 Multi-year climate oscillations such as the El Niño- Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) affect precipitation and stream discharge rates in the western hemisphere. While inferences may be drawn between these hydroclimatologica ... Full text Cite

Diurnal hysteresis between soil CO2 and soil temperature is controlled by soil water content

Journal Article Geophysical Research Letters · September 16, 2007 Recent years have seen a growing interest in measuring and modeling soil CO2 efflux, as this flux represents a large component of ecosystem respiration and is a key determinant of ecosystem carbon balance. Process-based models of soil CO2 production and ef ... Full text Cite

Evidence of optimal water use by vegetation across a range of North American ecosystems

Journal Article Geophysical Research Letters · April 16, 2007 We present empirical evidence for a relationship between the modal (most frequent) soil moisture level and the soil moisture level at which maximum evapotranspiration occurs for twenty-four flux tower sites in North America. We considered correlations and ... Full text Cite

A dynamic soil water threshold for vegetation water stress derived from stomatal conductance models

Journal Article Water Resources Research · March 1, 2007 [1] In many terrestrial ecosystems, vegetation experiences limitation by different resources at different times. These resources include, among others, light, nutrients, and water. Frequently, however, leaf-level modeling frameworks that unite these limita ... Full text Cite

Carbon dioxide exchange and early old-field succession

Journal Article Journal of Geophysical Research: Biogeosciences · March 28, 2006 Old-field succession is a widespread process active in shaping landscapes in the eastern United States, contributing significantly to the terrestrial sink of atmospheric carbon dioxide, particularly at midlatitudes. However, few studies document ecosystem- ... Full text Cite