Water Use Optimization

This research is funded by the DOE Waterpower Program. A key challenge taken by our multi-laboratory research team is to push beyond the status quo of using simple fixed constraints on operations to protect environmental resources of concern and, instead, identify and incorporate "environmental objectives" that address the complexity, variability, and uncertainty of the relationships between the operations of hydropower facilities and desired environmental conditions. To accomplish this, we will incorporate the ability to simultaneously consider multiple environmental relationships into the integrated suite of models being developed in this study. Our hypothesis is that both environmental performance and hydropower value can be improved by using the proposed tools to guide operations. ORNL's role in this effort builds on previous modeling research to optimize flows for salmon by thinking "outside the channel" and quantifying the role of floodplain inundation on riparian habitat and production of juvenile fish. This aspect of river dynamics is not addressed by the instream flow incremental methodology. On the energy side, we are considering seasonal fluctuations in value and loss of energy associated with water that spills (bypasses turbines). Our optimization model accounts for both the energy value and environmental sides of the equation as it shapes pulse flows. In addition, we have reviewed efforts to assign ecological values to salmon production. This will permit energy and ecological objectives to be assessed in the same currency.

More information about ORNL's role in the optimization project is available here pdf. and the Water power program at ORNL is described here.

Projecting Water Quality and Aquatic Biodiversity

This research is funded by the DOE Office of Biomass Programs. It is designed to address an important future challenge for the U.S. and other nations over the coming decades: how to determine whether bioenergy supplies meet sustainable production standards that include consideration of biodiversity.  Our research focuses on major river basins draining to the Gulf of Mexico.  We implemented the watershed model, SWAT, and added dedicated bioenergy crops, including switchgrass, poplar, willow, and energy sorghum. Our approach uses SWAT to simulate changes in water quality associated with changes in crop/land cover. We rely on an economic optimization model (POLYSYS) to forecast future entry of bioenergy crops into the agricultural landscape based on which crop brings the best price.  For each future landscape, we used the SWAT model to forecast changes in water quality. In collaboration with Argonne National Laboratory, SWAT will be implemented for other river basins draining to the Gulf of Mexico and we hope to evaluate potential for 2nd generation cellulosic perennial biofuel production to enhance water quality and biodiversity downstream.

To understand bioenergy influences on aquatic biodiversity, we developed empirical models to describe geographic variation in fish biodiversity in relation to water quantity and quality, landuse, and other factors. Our biodiversity modeling uses Natural Heritage data assembled by NatureServe. In a related effort, fishing license sales and activity days collected by states was used to monetize the ecological value of preserving fish diversity through best management practices in bioenergy. Our research team includes Peter Schweizer and Latha Baskaran, with help from Craig Brandt, Bob Perlack, Laurence Eaton and others. We organized a session at the 2010 meeting of the International Association of Landscape Ecologists in Athens entitled "Shifting Landscapes: Bioenergy and Biodiversity", which can be viewed here.
We are organizing a formal debate at the 2012 meeting of the Ecological Society of America in Portland to debate whether Producing bioenergy can be sustainable for habitat availability and biodiversity, and can eschew the risk of new invaders

More information about the larger ORNL program is available here and the Center for BioEnergy Sustainability (CBES) is described here.

Population Viability Analysis of Snake River Fall Chinook Salmon

Idaho Power Company is supporting the development of a metapopulation PVA model for Snake River Fall Chinook Salmon.  Using this model, we are quantifying the long-term extinction risk for this threatened species with the existing spatial structure.  In addition, we have using the model to examine circumstances under which the ESU would benefit from adding a new population.  Recent years of high spawner returns have allowed us to better define the spawner-recruitment relationship for this ESU, which has been incorporated into the metapopulation PVA.  We are  examining different assumptions about migration and straying among populations.  In addition, the influence of juvenile life history diversity (individuals following a "reservoir-type" life history by overwintering in reservoirs) is being examined.  Alex Perkins developed a temperature-driven model of juvenile growth and development to identify decision thresholds and predict what proportion of juveniles will exit as sub-yearlings and what proportion will residualize.  Jim Chandler and Phil Groves (IPC) have provided information needed to model Snake River fall Chinook and many years of experience with this population.

Other Recent Projects

Development of a Population Model for San Joaquin fall Chinook Salmon

The California Department of Fish and Game, headed by Dean Marston, is developing a full-lifecycle population model for fall Chinook salmon in the San Joaquin River and its three tributaries. ORNL provided guidance and relationships for the inland portion of the model. In particular, results included a metaanalysis and review of primary studies of temperature influences on egg and alevin development and survival, as well as thermal tolerances. Uni-modal survival relationships were fitted to data from all of these studies.

Population Viability Analysis of the Shortnose Sturgeon in the Ogeechee River

Predicting population response to summer water quality required simulating growth, movement, reproduction, and survival of individual sturgeon in response to gradients in temperature, salinity and dissolved oxygen in the Ogeechee River.  We simulated water quality using empirical models based on measurements taken throughout 2008-2009. In addition, a study of headwater watersheds on Fort Stewart related nutrient and sediment concentrations draining watersheds to watershed attributes including vegetation, road densities, and military training.

The EFDC water quality model will simulate salinity changes caused by rice canals that link the Little Ogeechee and the Ogeechee rivers.  A bioenergetic and mercury-uptake model developed for shortnose sturgeon was used to estimate egg concentrations and potential reproductive effects.  The supporting field component of this effort measured methyl mercury concentrations in amphipods along a salinity gradient in the Ogeechee River.  We found that our bioenergetic-mercury uptake model produced reasonable predictions of gonadal concentrations, which were not sufficiently high to cause concern.

Shortnose sturgeon killed by shad net captures were simulated using a individual-based and spatially explicit PVA model based on data from net surveys conducted in late-winter and spring, 2008. This project was a collaborative effort with Doug Peterson at the University of Georgia, Mark Bevelhimer and myself at ORNL, and the Natural Resources Branch at Fort Stewart, with support from the UGA Marine Extension at Brunswick (chemical analyses) and Dynamic Solutions LLC (EFDC implementation).  Daniel Farrae (UGA) and Roy King (ORISE) conducted field surveys and collecting water samples, respectively.

(read SERDP fact sheet)

(read Science Daily article)

Watch our movies of the Ogeechee River (avi format):

Daniel Farrae's maps of shortnose sturgeon habitat suitability

Mark Bevelhimer's EFDC maps of salinity with rice canals and without rice canals:

Ecological Valuation

In this ORNL seed project, headed by Rebecca Efroymson, we examined the potential use of ecological models to derive relative values for animal populations and their habitat.   Ecological models were used to transfer values from populations to habitat and vice versa, and to examine how extinction thresholds influence use and non-use values, measured by willingness-to-pay surveys.  Efroymson, Jager and Hargrove reviewed and projected future use of population and landscape models in valuation of wildlands.  Jager, Oladosu and Efroymson demonstrated the combined use of a population model and an economic model in a case study involving Chinook salmon.  The age-based population model showed that equilibrium population sizes increased with total annual flow, whereas minimum viable population size decreased with total annual flow.  Marginal willingness to pay for equilibrium population size was optimal at an intermediate, but relatively low level of annual flow, whereas marginal willingness to pay for minimum viable population size decreased with flow.

Population Viability Analysis (PVA) of Snake River White Sturgeon

We developed a PVA model for white sturgeon populations in the Snake River to evaluate management alternatives that have been proposed as part of relicensing for Middle Snake River dams.  We used the PVA model to quantify the effects of habitat fragmentation by dams on white sturgeon (Jager et al. 2000) in a theoretical river system. In 2001, we used the model to evaluate the relative effects of various factors that have been implicated as playing a role in population declines in some river segments (Jager et al. 2001). In 2002-2003, we simulated realistic strategies designed to reconnect fragmented populations, (translocation and fish passage) with and without other mitigation actions (e.g., reduced trash-rack spacing, improved water quality). These simulations provided the White Sturgeon Technical Advisory Committee with information needed to recommend conditions for relicensing dams in the Middle Snake River. The model has since been used to evaluate reconnection strategies involving translocation or upstream passage in rivers with different configurations.  In 2003-2004, the PVA model was used to evaluate demographic and genetic costs and benefits of sturgeon aquaculture.

Because there are a number of different factors that potentially influence white sturgeon in each river segment, we designed specific models to address those questions. Mark Bevelhimer developed a bioenergetic model to quantify the effects of load following operations on white sturgeon growth and reproduction. He found that temperature differences among the river segments alone explain significant differences in reproductive potential over the lifetime of a female (Bevelhimer 2002). This information feeds into the PVA model to quantify population-level effects.  Annett Sullivan developed a spatial model designed to quantify the effects of water quality in Brownlee Reservoir. She found that predictions of population-level effects to depend on model assumptions about movement (Sullivan et al. 2003).

Our latest research has focused on understanding the effects of small population size on extinction risk for white sturgeon in the Columbia River basin .  We have compiled data for nearly all populations of white sturgeon to better understand 1) whether there is a minimum viable population size and 2) how habitat and metapopulation support influence extinction risk.  The PVA model has also been used to examine this question for Snake River populations.

(read more)

DOE Hydropower – Environmental Mitigation and Hydropower Optimization

Mark Bevelhimer led an effort to quantify the costs and benefits of instream-flow mitigation practices on hydropower generation and on biological communities. I used intervention analysis to test for a significant change in annual generation, accounting for year-to-year variation in flow as a covariate. Relicensing usually had a negative effect on generation, presumably due to flow mitigation, but that the decrease was rarely significant, even after removing the effects of year-to-year variation in climate (flow). For hydropower projects (i.e., dams) that changed from peaking to run-of-river operations, we evaluated changes in the proportion of flow released during peak demand using sub-daily flow data from USGS. Results showed a reduction in this proportion following relicensing primarily at dams with large storage capacity and no upstream regulation. In several cases, the proportion increased at dams passing through flow fluctuations from upstream projects. I also reviewed efforts to optimize hydropower operations for biological objectives, or to constrain operations to protect biological resources.

Species Conservation and the effects of Petroleum Extraction on Bureau of Land Management Lands

Rebecca Efroymson led ORNL’s role in this collaboration between LLNL (Tina Carlson), BLM, and ORNL.  We are using spatially explicit, individual-based models to study the effects of habitat loss and fragmentation on bird and mammal populations of conservation concern, including the prairie dog (LLNL) and the sage grouse (ORNL).   We developed a generalized population viability analysis (PVA) model that permits individuals to be social in some seasons (breeding, primary feeding, winter) and solitary in other seasons.  We parameterized this model for sage grouse in the Uintah Basin, Utah and used the model to predict minimum viable population sizes for the species.  The model-derived estimates were compared with those published in field studies.

Testing and Improvement of the Oak Ridge Chinook salmon Model (ORCM) in the Tuolumne River, California

The ORCM was developed between 1995 and 2000 and used to predict seasonal patterns of flow that would maximize Chinook salmon recruitment from the Tuolumne River below New Don Pedro Dam. Since that time, nearly ten years of monitoring have been conducted by Tim Heyne and others at the California Department of Fish and Game, including rotary screw trapping of outmigrating juveniles. This study, funded by the California Energy Commission, had two objectives. First, I compared ORCM predictions to these monitoring data, evaluated discrepancies, and made improvements to the model or its parameters.  We conducted a functional validation in which we compared model and data relationships between (measured or predicted) salmon outmigration and flow, spawner density and degree-days. Autocorrelation in predictors were accounted for in the analysis. After two sets of comparisons, agreement was adequate for some years, but considerable differences remained for others. Second, we developed imputation equations to use in estimating smolt outmigration. Third, I implemented a routine to estimate the hydropower generation value associated with simulated flow regimes.

Spatial Uncertainty in Ecological Models

The goal of this project was to evaluate the role of spatial uncertainty or error on projections from PVA and other ecological models used by DoD.  As part of this SERDP-funded project, we (Tony King, Tom Ashwood, Barbara Jackson and me) developed a method for generating stochastic simulations to be used in spatial uncertainty analysis.  This approach was published in Ecological Modelling in 2005.   We found that population viability models were most sensitive for landscapes whose average spatial statistical properties placed them near extinction thresholds (e.g., subject to Allee effects).

Developing an Ecological Framework to Evaluate the Impacts of Releases at Upstream Exploration and Production Sites

We developed an ecological framework to evaluate the impacts of releases at petroleum exploration and production sites. The project team at ORNL was headed by Rebecca Efroymson and is using a case study at the Nature Conservancy's Tallgrass Prairie Preserve in Oklahoma We collaborated with Tina Carlsen and Tanya Kostova at Lawrence Livermore National Laboratory. We developed a landscape model for birds or mammals, with help from Eric Carr, and evaluated the simulated effects of habitat loss and fragmentation on American badger populations. We found that the decline of population viability was steeper on fragmented landscapes, particularly for a species like the American badger that does not avoid poor or risky habitat. We also quantified Allee effects caused by the failure to find mates in disturbed landscapes, which suggests that the presence of unmated females defending territories might be an early warning sign that densities are too low (Jager et al. Ecological Modelling).

Conceptual PVA for Pallid Sturgeon

In this project, I worked with Steve Krentz to develop a Population Viability model for pallid sturgeon. The model which simulates hybridization between pallid and shovelnose sturgeon and hatchery stocking. The pallid sturgeon is listed under the Endangered Species Act and its recovery is the concern of recovery teams throughout the Mississippi and Missouri River basins. This study was funded through the ORNL State Partnership Program, and involved collaborators at the Western Area Power Administration (Ted Anderson) and US Fish and Wildlife (Steven Krentz, Pallid sturgeon Recovery Team Leader).