ABSTRACT:

Session: CUAHSI Summer Institute at the National Water Center
Chair: Jerad Bales (CUAHSI)
The 2018 CUAHSI Summer Institute (SI) was held June 10 – July 26, 2018 at the National Water Center on the Tuscaloosa campus of the University of Alabama. Twenty-five graduate students, two course coordinators, nine faculty theme leaders, and three CUAHSI staff participated, as well as a number of guests from the NWS, USGS, and elsewhere. Students at the 2018 SI focused on hyper-resolution modeling, groundwater – surface connections, data from volunteer monitoring, and river hydraulics. Students used National Water Model outputs and observations to explore potential improvements to the NWM and to describe uncertainty. Among the data sets utilized was the CUAHSI-curated Hurricane Harvey hydrometeorological data from 2017. The session will begin with a presentation from Dr. Thomas Graziano, Chief of the NWS Office of Water Prediction, followed by presentations by selected 2018 students.

"Evaluating Alternative Baseflow Estimation Methods for Improving National Water Model Forecasting"
Speaker: Joseph M. Krienert (Southern Illinois University)
Co-Authors: Minki Hong (Texas A&M University), Ritesh Karki (Auburn University), and Sama S. Memari (University of Alabama)

The National Water Model (NWM) became fully operational in August of 2016. This hydrologic model uses a framework of real time climatic data and observed physiographic attributes to produce forecasts of surficial fluvial systems across the Contiguous US. Comparison of the NWM streamflow estimations with USGS observed datasets has shown that the NWM estimates are not entirely accurate, especially during low flow conditions. A potential influence on this miscalculation lies in the NWM’s conceptual (not physicallyexplicit) estimation of baseflow to streams, and this non-linear conceptual baseflow model only expresses a part of the interaction between groundwater and surficial hydrology.

This research evaluates the current representation groundwater discharge in the NWM with a case study of five watersheds located within the Northern High Plains region. A comparison between USGS observed stream flow, a systematically calibrated groundwater model (Peterson et al 2016), and the output hindcasts of the NWM will be used to evaluate the current model’s fitness in representing surface water - groundwater interaction in gaining streams; with a particular focus on baseflow estimation. Based on the results of this analysis, formulation of alternative functions representing the relationship between subsurface storage and groundwater discharge will be tested for potential improvements in future updates of the NWM.

ABSTRACT:

Dynamic Connectivity in the Landscape
Chair: Adam Ward (Indiana University)
Connectivity between different locations on the landscape is defined by the movement of water, solutes, energy, and organisms. The magnitude and persistence of connections is critical to prediction of ecological functions, many of which are mediated by hydrological stores and fluxes. In this session we consider connectivity as a spatially and temporally variable process in catchments and river systems.

"Ecohydrological connectivity between landscapes and riverscapes"
Speaker: Doerthe Tetzlaff (University of Aberdeen)

It is increasingly recognised that the processes and connections in our landscapes are influencing the functioning of aquatic ecosystems. Fundamental scientific understanding of the functioning of both aquatic and terrestrial ecosystems is required for an integrated and sustainable management of landscapes and riverscapes to maintain their ecosystem services and biological integrity at multiple scales. This talk will show how the connectivity in ecohydrological systems can be quantitatively assessed through a number of novel, integrated approaches. Importantly, this talk will discuss the need to understand the role of vegetation in regulating the connectivity between terrestrial and aquatic ecosystems. Environmental tracers are valuable tools to understand the functioning of ecohydrological systems at the landscape scale in terms of understand flow paths, sources of water and associated biogeochemical interactions. Extensive empirical studies were conducted at the plot and hillslope scale to understand ecohydrological systems, and in particular, soil-vegetation-water connections. This empirically based understanding was then integrated into spatially distributed, tracer-aided models to understand mixing of water, flows to the stream and water age distribution at the catchment scale. We use the physically-based, distributed tracer-aided ecohydrologic model (EcH2O-ISO) which we have extended to track 2H and 18O (including fractionation processes) and water age. EcH2O-ISO combines a hydrologic scheme with an explicit representation of plant growth and phenology while resolving the energy balance across the soil-vegetation-atmosphere continuum. We also implemented isotope routing, mixing and fractionation (and used flux tracking for mean water age calculation). This tracer-aided modelling allows us to simulate stream and soil isotope responses very well and at some sites can account for the composition of xylem water. Our simulations showed contrasting time-variant age distributions of water exiting catchments as evapotranspiration and stream flow; these differences are strongly influenced by vegetation cover and other landscape controls (topography, soils, geology).

ABSTRACT:

Dynamic Connectivity in the Landscape
Chair: Adam Ward (Indiana University)
Connectivity between different locations on the landscape is defined by the movement of water, solutes, energy, and organisms. The magnitude and persistence of connections is critical to prediction of ecological functions, many of which are mediated by hydrological stores and fluxes. In this session we consider connectivity as a spatially and temporally variable process in catchments and river systems.

"Dynamic lateral, vertical, and longitudinal hydrologic connectivity drive runoff and carbon export across watershed scales"
Speaker: Margaret Zimmer (University of California Santa Cruz)

The influence of temporally dynamic lateral, vertical, and longitudinal connectivity of runoff source areas on hydrologic and biogeochemical fluxes across watershed scales is poorly understood. To address this, we monitored the timing, magnitude and chemical composition of precipitation, runoff, and runoff-generating flow paths in nested 3.3 and 48.4 ha watersheds (North Carolina, USA). These watersheds are comprised of ephemeral and intermittent runoff-producing headwaters and perennial runoff-producing lowlands. We monitored the active surface drainage network, which reflected connectivity to, and contributions from, runoff source areas that shifted within baseflow and stormflow conditions. The overall importance of deeper, baseflow-associated and shallower, stormflow-activated source area contributions varied across watershed scales and influenced dissolved organic carbon (DOC) export. The dominant temporal variability of in-stream DOC was driven by frequent event-based flushing of shallow soil zones and annual replenishment. Our findings suggest that hydro-biogeochemical signals at larger watershed outlets can be driven by the expansion, contraction, and connection of lateral, longitudinal, and vertical source areas that reflect distinct runoff generation processes.

ABSTRACT:

Dynamic Connectivity in the Landscape
Chair: Adam Ward (Indiana University)
Connectivity between different locations on the landscape is defined by the movement of water, solutes, energy, and organisms. The magnitude and persistence of connections is critical to prediction of ecological functions, many of which are mediated by hydrological stores and fluxes. In this session we consider connectivity as a spatially and temporally variable process in catchments and river systems.

"Drivers of Dynamic Disconnectivity in Rivers
Speaker: Ellen Wohl (Colorado State University)

As the science of hydrologic connectivity has developed, there is sometimes a tendency to under-emphasize the importance of disconnectivity. Connectivity and disconnectivity can both be characterized in terms of magnitude, frequency, duration, timing, directionality, and dimension. The latter characteristic is important because features that create longitudinal disconnectivity in rivers, for example, can enhance lateral and vertical connectivity. Here, I discuss naturally occurring processes that limit longitudinal connectivity in river corridors and the effect of these longitudinal disconnections on river form and function. Examples of such processes include lateral channel movement and the associated secondary channels, avulsions and cutoffs; lateral sediment inputs from tributaries or adjacent hillslopes that create alluvial fans in the river corridor; logjams; and beaver dams. I focus on logjams and beaver dams using case studies from mountain streams in the Southern Rockies. River networks in this high-relief terrain are predominantly steep, narrow canyons with high longitudinal connectivity and limited lateral connectivity between channels and floodplains or vertical connectivity between channels-floodplains and the hyporheic zone. Wide, low-gradient valley segments scattered throughout the network provide retention zones in mountainous river networks and typically exhibit greater lateral and vertical connectivity than the intervening steep, narrow segments. The details of connectivity, however, and the magnitude of retention and the partitioning of retained water, solutes, sediment, and organic matter among alluvial storage and atmospheric emissions depend in large part on the presence of features that limit longitudinal connectivity, as such as logjams or beaver dams. Through research conducted during the past decade, we have found that channel-spanning logjams and beaver dams substantially decrease downstream transport of water, solutes, sediment, and organic matter during both base flows and snowmelt peak flows. At the same time, logjams and beaver dams substantially increase channel-floodplain and channel-hyporheic exchange and thereby increase retention and long-term (102-103 year) alluvial storage of sediment and organic carbon. One implication of these findings is that river management can be designed to limit longitudinal connectivity in ways that foster ecosystem services such as flood attenuation, reduction of downstream sediment, nitrate, and carbon fluxes, and increased habitat abundance and diversity.

ABSTRACT:

Food-Water Systems
Chair: Megan Konar (University of Illinois)
This session will explore interactions and interconnections between food and water systems. Cutting edge research will focus on identifying resiliencies and vulnerabilities in the water-food nexus and opportunities to promote sustainable water use while enhancing food security.

"Holistic Pathways for Achieving Food Security and Water Sustainability"
Speaker: Kyle Davis (Columbia University)
Co-Authors: Paolo D’Odorico (University of California Berkeley), Ashwini Chhatre (Indian School of Business, Hyderabad), Davide Danilo Chiarelli (Politecnico di Milano), Narasimha Rao (International Institute for Applied Systems Analysis), Brian Richter (Sustainable Waters), Lorenzo Rosa (University of California Berkeley), Maria Cristina Rulli (Politecnico di Milano), Antonio Seveso (Politecnico di Milano), Deepti Singh (Lamont-Doherty Earth Observatory of Columbia University and Washington State University), Ruth DeFries (Columbia University)

Global food supply has nearly tripled over the past half century, supporting massive population growth, richer diets, and the expansion of alternative crop-based energy sources. At the same time, one in nine people still cope with chronic undernourishment, and the environmental burden of agriculture has grown substantially. There is wide agreement that humanity’s rate of resource use exceeds what can be sustainably generated and absorbed by Earth’s systems. It is also clear that a continuation of current agricultural practices will enhance the vulnerability of the global food system to economic and environmental shocks. A radical transformation of the global food system is therefore required in order to increase nutritious food production while minimizing its impacts on water resources and the environment and accommodating uncertainties related to demand and climate change.

Aligning these goals demands a holistic perspective that combines diverse lines of scientific evidence with direct stakeholder engagement. I will present some of my recent research that attempts to address this challenge by quantifying historical impacts and tradeoffs of food systems, assessing solutions that can achieve co-benefits for food security, livelihoods, and water resources, and identifying potential suitable policy pathways for their implementation. Combining global assessments and case studies at policyrelevant scales, I will introduce a multidimensional framework that values multiple types of knowledge and that emphasizes interactions with local experts. This approach seeks to integrate food security, economic, social, and environmental considerations in order to examine the outcomes of existing agricultural policies as well as expand the suite of feasible solutions. In doing so, this work offers insights for developing effective food security strategies that are receptive and responsive to the priorities of local governments and communities and that enhance the sustainability and adaptability of food and water systems.

ABSTRACT:

Hydrologic Extremes and Society
Chair: Hilary McMillan (San Diego State University)
This session focuses on observations, prediction, communication and adaptation to hydrologic extremes. By bringing together ideas from flood and drought research, we analyze similarities and differences in societal impacts and interactions with these two extremes. We explore how providing observations and information about hydrologic extremes can change the way societies understand and react to crisis events.

"Compound and Concurrent Climate Extremes: Detection, Modeling and Risk Analysis"
Speaker: Amir AghaKouchak (University of California Irvine)

Human activities in the past century have caused an increase in global temperature. Ground-based observations show a substantial increase in extreme rainfall events, hot spells and heatwaves. A combination of climate events (e.g., low precipitation and high temperatures) may cause a significant impact on the ecosystem and society, although individual events involved may not be severe extremes themselves – a notion known as compound event/extremes. Numerous studies have focused on how different types of extremes have changed or might change in the future. However, only few studies have addressed changes in compound and concurrent events. This presentation focuses on three different types of concurrent and compound extremes including droughtheatwaves, sea level rise-terrestrial flooding, and meteorological-anthropogenic drought. We present different methodological frameworks for detecting, modeling and risk assessment of concurrent and compound extremes using ground based and remote sensing observations.

ABSTRACT:

Hydrologic Extremes and Society
Chair: Hilary McMillan (San Diego State University)
This session focuses on observations, prediction, communication and adaptation to hydrologic extremes. By bringing together ideas from flood and drought research, we analyze similarities and differences in societal impacts and interactions with these two extremes. We explore how providing observations and information about hydrologic extremes can change the way societies understand and react to crisis events.

"Tracking Drought Impacts Across Space, Time, Sectors and Scales"
Speaker: Kelly Smith (University of Nebraska Lincoln)

In the 1990s and early 2000s, drought disaster researchers called for creation of a comprehensive database of drought impacts. But creation of such a database presumes that there is a single perspective from which all impacts will be visible. In fact, drought impacts are like fractals – as you focus on smaller scales, new realms of detail become apparent. An individual farmer’s drought-related loss or the hardship that an agricultural community experiences may be completely lost when drought impacts are aggregated to a national scale. Furthermore, drought impacts occur within specific contexts – a household has to water landscape and garden plants more; a reservoir operator produces less hydropower; fish die because a river dried up; fewer lift tickets are sold when there is no snow; and so on. Decision-makers in each of these sectors may or may not consider drought – an abstraction, often one of many pressures – as causing a separate impact, and they typically describe its effects, nested within a context that includes both long- and short term institutional effects. And many people have the adaptive capacity to foresee and prevent losses – a ski resort may offer hiking opportunities instead – so lack of water does not always translate into a drought impact. While this may seem obvious, it means there is no common framework for identifying, let alone quantifying, drought impacts. Sector and scale both matter. Large-scale commodity crops and hydropower production are some of the easiest drought impacts to quantify. Health effects to individuals and ecosystems are some of the hardest. Data collection requires resources, and in the absence of unlimited resources, we need to determine what data needs to be collected – or analyzed – to manage drought impacts.

ABSTRACT:

Hydrologic Feedbacks with Ecosystems
Chair: Gretchen Miller (Texas A&M University)
Advancements in ecohydrology have highlighted the importance of feedbacks between vegetation and the hydroclimate, with their subsequent impacts on water and food supplies. In this session, we discuss these feedbacks across a range of ecosystems and scales, highlighting recent and developing improvements in their modeling.

"Improving the representation of vegetation-atmosphere interactions through plant-hydrodynamics models"
Speaker: Ashley Matheny (University of Texas at Austin)

Vegetation provides a critical pathway for water transport from the land surface to the atmosphere; yet, the ability of vegetation to actively modulate water uptake and release makes this a challenging process for land-atmosphere models to capture. Recently, a number of physical process models of water flow through vegetation have come to the fore. These models draw a parallel between vegetation’s conductive tissues and porous media. The FETCH2 scalable vegetation model uses a simplified form of the Richards equation to simulate water movement within trees while allowing for dynamic changes in hydraulic conductance and capacitance. In this manner, FETCH2 can capture divergent hydrodynamic behaviors among species in the same ecosystem in manners that standard land-atmosphere models cannot. FETCH2 and other mechanistic vegetation models stand to promote significant improvements to our ability to model transpiration at local to global scales. In particular, this new class of plant hydraulics models stands to revolutionize the way models capture the effects of drought, land use and land cover change, and climate change on the hydrologic and carbon cycles as well as on vegetation demography.

ABSTRACT:

Hydrologic Feedbacks with Ecosystems
Chair: Gretchen Miller (Texas A&M University)
Advancements in ecohydrology have highlighted the importance of feedbacks between vegetation and the hydroclimate, with their subsequent impacts on water and food supplies. In this session, we discuss these feedbacks across a range of ecosystems and scales, highlighting recent and developing improvements in their modeling.

"Plant water use and plant water status during protracted and seasonal droughts: A link between hydrological fluxes and ecological disturbance"
Speaker: Sally Thompson (University of California Berkeley)

Ecohydrology has two important, related insights to offer the study of global change: (i) prediction of plant vulnerability to changes in the water cycle, and (ii) descriptions of the water cycle that account for the role of plants in regulating water fluxes. The link between these issues is the internal water status of plants, which controls water uptake and the physiological experience of stress. The relationship between water status and water uptake, however, is strongly mediated by plant physiological characteristics and a plant’s environmental setting. Here I will draw on a combination of modeling and observational studies of Californian vegetation during seasonal and multi-year drought to (i) show how different physiological characteristics can de-couple trajectories of plant water potential and transpiration, (ii) illustrate how different landscape and hydrological settings influence the crossing of water potential thresholds, xylem recovery and ultimately plant health during multi-year drought, and (iii) highlight some challenges associated with reconciling the ecohydrological and ecophysiological communities’ approaches to describing plants and plant water fluxes during drought.

ABSTRACT:

Instrumentation Panel
Chairs: Elizabeth Boyer (Pennsylvania State University) and Scott Tyler (University of Nevada Reno)

"National Scale Multi-User Facilities of Interest to the Hydrological Community"
Investments from the National Science Foundation and other agencies provide state-of-the-art tools and models for research and education. This session will feature an overview of multi-user research facilities, distributed instrumentation networks, collaboratories, and laboratories of interest in the hydrologic sciences. Representatives of each facility will describe their capabilities and the process for using the facility, and will provide examples of applications in the hydrologic sciences. We encourage all meeting participants to make use of these facilities, and to help spread the word about their availability.

Panelists:
Bruce Beaudoin (IRIS PASSCAL)
Glen Mattioli (UNAVCO)
John Selker (CTEMPs)
Janice Fulford (USGS Hydrologic Instrumentation Facility)
Brigitte Baeuerle (NCAR)
Craig Glennie (National Center for Airborne Laser Mapping)
Anders Noren (Continental Scientific Drilling Coordination Office)
Mike Olson (National Atmospheric Deposition Program)
Nick Harrison (National Ecological Observatory Network)
Chris Wilson & Miguel Leon (Critical Zone Observatories)
Albert Kettner (Community Surface Dynamics Modeling System)

ABSTRACT:

Keynote Lecture
"Engineering and Policy Decisions at the Energy-Water Nexus"
Speaker: Jeanne M. VanBriesen

Coal-fired power plants are under increasing pressure to manage air quality emissions while remaining profitable in a competitive electricity market. Engineering and policy choices designed to support these objectives can have unexpected effects on pollutant discharges to surface waters that are used as sources at drinking water treatment facilities.

Of particular concern is the release of bromide from coal-fired power plants operating wet flue gas desulfurization (FGD) units. Bromide, while unreactive in surface waters, interacts with treatment chemicals at the drinking water facility to produce halogenated organic compounds called disinfection by-products (DBPs). DBPs containing bromide are more toxic and carcinogenic than chlorinated DBPs, and the current regulatory structure may not adequately protect drinking water consumers from this changing risk.

Bromine, which is naturally present in coals, is not removed in FGD wastewater prior to discharge. Recently, new technologies based on bromide addition have been deployed at power plants to reduce airborne mercury releases and to qualify for federal tax credits. The addition of bromide can significantly increase bromide loading to surface waters and negatively impact drinking water facilities and
consumer risk.

Watershed-, state-, and national-level analyses will be presented that highlight the critical characteristics of regions where current bromide loads are affecting drinking water consumers as well as regions at risk for impacts under future plans for bromide addition and FGD wastewater discharges. The work is particularly timely as the U.S. EPA is re-considering the Effluent Limitation Guidelines for Steam Electric Power Utilities, which currently do not require control of bromide discharges from FGD systems.

ABSTRACT:

Measurement-Monitoring-Sensing
Chair: Branko Kerkez (University of Michigan)
This session will explore how the latest generation of sensors is reshaping the study hydrologic systems at unprecedented spatial and temporal resolutions. We will discover how the Critical Zone is being measured across massive scales. We will learn about 3D printed sensors, which to democratizing measurements across the world. We will also hear how federal researchers are using a new generation of water quality sensors to support discovery and management.

"Development of Innovative Low-cost Hydrometeorological Sensors to Improve Monitoring in Data-sparse Regions"
Speaker: Paul Kucera (UCAR)

Accurate and reliable real-time monitoring and dissemination of observations of atmospheric and hydrologic conditions in general is critical for a variety of research and decision support applications. Combined precipitation and stream gauge observations provide information about the hydrological cycle in a basin and are critical for a variety of hydrometeorological applications. In many regions of the World, weather station, precipitation gauge, and stream gauge networks are sparsely located and/or of poor quality. Existing stations have often been sited incorrectly, not well-maintained, and have limited communications established at the site for real-time monitoring. The University Corporation for Atmospheric Research (UCAR) with support from USAID, has started an initiative to develop low-cost hydrometeorological instrumentation including tipping bucket and weighing-type precipitation gauges along with stream gauges as solution to increase observation networks in sparsely observed regions of the world. The goal of the project is to improve the number of observations (temporally and spatially) in these regions to improve the quality of applications for environmental monitoring and early warning alert systems on a regional to global scale. One important aspect of this initiative is to make the data open to the community. The hydrometeorological instrumentation have been developed using innovative new technologies such as 3D printers, Raspberry Pi computing systems, and wireless communications. The presentation will provide an overview of the new observation technology and experiences with sensor the performances.

ABSTRACT:

Reds Wolman Lecture
Background: The Wolman Lecture is named after M. Gordon “Reds” Wolman (1924-2010). Wolman was a prominent and much-beloved fluvial geomorphologist who taught at Johns Hopkins University from 1958 until his death in 2010. He advanced the quantitative and interdisciplinary study of rivers, contributed to solving a multitude of water management problems around the world, and was well-known for his insight, humor, and thoughtful mentoring of dozens of graduate students.

"A water-centric view of the climate-FEW-society nexus"
Speaker: George M. Hornberger (Vanderbilt University)

Food, energy, and water (FEW) are primary resources required for human populations and ecosystems. The large and growing water demands for agricultural production are well known, water can be a significant constraint in electricity production, and the use of arable land for biofuels represents tradeoff decisions at the FEW nexus. Climate change will affect water availability. Increased demand for FEW resources from population growth and lifestyle changes will result in increased competition for limited resources, which will impact financial decisions. Both water quantity and water quality considerations of FEW interactions need to be taken into account explicitly because there are important feedbacks between quantity and quality aspects of the interactions. It is also important to take FEW resources into account during adaptation planning, as highlighted by recent events in the US when many citizens lost ready access to food, electricity, and drinking water in the aftermath of Hurricanes Harvey, Irma, and Maria.

Managing the FEW resources concurrently is a seemingly wicked problem involving an apparent trilemma from a sustainability and resiliency perspective. A core challenge is to develop an integrative understanding that embodies processes and feedbacks at a level of detail that allows evaluation of alternatives in these complex systems and therefore can support integrated management.

Advances in hydrological science clearly are critical to the enterprise of determining how to achieve global goals for developing and using FEW resources sustainably, especially in the face of a changing climate and a growing population. Among the needs are new and expanded data acquisition, analyses and syntheses of multi-sectoral data and information, and integrative modeling. In my presentation, I will review some of the critical needs and illustrate them using a few nascent research results.

ABSTRACT:

Water and the Changing Climate
Chair: Jeanne VanBriesen (Carnegie Mellon University)
Global climate change is changing the frequency and magnitude of precipitation events in many regions, and further change is expected. Effects on precipitation-dependent events (drought, flood) as well as on rainfall-dependent systems (water supply, energy systems, agriculture) will challenge our study and management of hydrologic systems. This session will explore methods to study, model, and plan for hydrologic systems under changing climactic conditions.

"Positioning Risk – Climate variability, Nonstationarity and Hydrological Extremes"
Speaker: Ana Barros (Duke University)

The notion of positioning risk in the context of nonstationarity and future climate is based on the premise that the metrics of risk change conditional on climate regime. The IPCC defines climate regime as a state of the climate system that occurs more frequently than nearby states due to either more persistence or more frequent recurrence, that is a local maximum in the probability density function. First, Global climate Model simulations of past and current climate are analyzed against observations to assess the predictability of multi-decadal to century scale climate regimes relevant to hydrological extremes (precipitation and streamflow) in the Southeast US. Next, we separately address high and low precipitation statistics and space-time variability conditional on climate regime and physiography, and explore the development of a framework for adaptively positioning risk in the assessment of future extremes that also incorporates understanding of regional and local hydrology.

ABSTRACT:

Water and the Changing Climate
Chair: Jeanne VanBriesen (Carnegie Mellon University)
Global climate change is changing the frequency and magnitude of precipitation events in many regions, and further change is expected. Effects on precipitation-dependent events (drought, flood) as well as on rainfall-dependent systems (water supply, energy systems, agriculture) will challenge our study and management of hydrologic systems. This session will explore methods to study, model, and plan for hydrologic systems under changing climactic conditions.

"Probabilistic modeling of hurricane surge and rainfall flooding in a changing climate"
Speaker: Ning Lin (Princeton University)
Co-Authors: Kerry Emanuel (Massachusetts Institute of Technology), James Smith (Princeton University), Joannes Westerink
(University of Notre Dame)

Hurricanes, with their strong winds, heavy rainfall, and storm surges, cause much damage and loss of life worldwide. The impacts of these storms may worsen in the coming decades because of rapid coastal development coupled with sea-level rise and possibly increasing hurricane activity due to climate change. Here we present a framework of modeling hurricane hazards in a changing climate. We apply a statistical/deterministic hurricane model driven by global climate models (GCMs) to simulate large numbers of synthetic storms under various projected climate scenarios. We apply the hydrodynamic model ADCIRC to simulate the coastal storm surge induced by the synthetic storms. We apply a physics-based hurricane rainfall model coupled with a distributed hydrologic model to simulate the riverine flooding induced by the synthetic storms. Then we apply statistical analysis to estimate the rainfall and surge flood probabilities under the various climate conditions, based on the simulated synthetic rainfall and storm surge events. We are currently coupling the coastal storm surge and inland rainfall modeling to investigate the compound flooding induced by hurricanes under climate change.

ABSTRACT:

Every two years, CUAHSI hosts a symposium to bring together the diverse fields of water science to discuss developments in the hydrology sector of the Earth Sciences. Under leadership from the CUAHSI Board of Directors, researchers present their latest findings and developments, propose community workshops, and interact with colleagues from different disciplinary fields from all over the country.

CUAHSI’s Biennial Colloquium offers a unique opportunity and a casual environment for participants to discuss ideas and network with colleagues, as well as build new relationships. Students are especially encouraged to attend and present posters.

CUAHSI's Sixth Biennial Colloquium was held on July 29 - August 1, 2018 at the National Conservation Training Center in Shepherdstown, WV.

Here you'll find presentations on "Hydrologic Connections: Climate, Food, Energy, Environment, and Society."

ABSTRACT:

Water and the Changing Climate
Chair: Jeanne VanBriesen (Carnegie Mellon University)
Global climate change is changing the frequency and magnitude of precipitation events in many regions, and further change is expected. Effects on precipitation-dependent events (drought, flood) as well as on rainfall-dependent systems (water supply, energy systems, agriculture) will challenge our study and management of hydrologic systems. This session will explore methods to study, model, and plan for hydrologic systems under changing climactic conditions.

"USACE Incorporation of Climate Change Impacts into Water Resources Analysis & Planning"
Speaker: Will Veatch (U.S. Army Corps of Engineers)

The assumption of hydrologic stationarity, that observed data from the past represents present and future conditions, has typically underpinned hydrologic and hydraulic design and planning. A growing body of scientific evidence is undermining that assumption, as certain variables critical to the design and evaluation of water resources projects are being impacted by climate change and anthropogenic watershed modifications such that future variability cannot necessarily be assumed to follow past observations. US Army Corps of Engineers (USACE) projects must, as a matter of policy, be designed for the full range of plausible future conditions that can be expected throughout their intended design lives, despite uncertainty regarding the exact nature of those future conditions. USACE has therefore released revised technical guidance related to the identification of observed changes and projection of potential future changes in hydro-climatic conditions. In addition to the written guidance, USACE has developed web applications that make it easier for water resources professionals to apply the techniques described in the guidance in a technically correct, timely, and reproducible manner. In this talk, USACE policy and technical guidance related to the incorporation of climate change impacts into hydrologic and hydraulic analysis for both coastal and inland waterways will be outlined, along with the web-based tools created to help implement these analyses. After attending this talk, the audience will be able to understand and use USACE technical guidance and publicly available tools for their own projects.

ABSTRACT:

Presentation by Briana K. Whitehead (Montana State University) on CUAHSI's Near Surface Geophysics for Hydrology Workshop in Laramie, WY in September 2018.