Wednesday, May 25, 2016
10:30 - 12:00

<< Back to Schedule

10:30 - 10:45: / 314 AGGREGATING DATA FROM MULTIPLE AGENCIES: IMPLICATIONS FOR DETECTING BIOLOLGICAL COMMUNITY CHANGE ACROSS A FLOW ALTERATION GRADIENT

5/25/2016  |   10:30 - 10:45   |  314

AGGREGATING DATA FROM MULTIPLE AGENCIES: IMPLICATIONS FOR DETECTING BIOLOLGICAL COMMUNITY CHANGE ACROSS A FLOW ALTERATION GRADIENT Determining the effects of flow alteration on macroinvertebrate communities often requires combining data from multiple agencies that use different subsample sizes and taxonomic resolution. We investigated how combining such disparate data sources affects the detection of responses across a hypothetical gradient of flow alteration. Responses were evident in ordination analysis when taxonomic levels and subsample sizes were consistent across data sources. However, mixing taxonomic levels and(or) subsample sizes introduced methodological gradients that obscured responses. Responses of richness metrics were affected by taxonomic resolution with response rates decreasing as taxonomic resolution decreased (species to genus to family) even when taxonomic levels and subsample sizes were consistent among data sources. Responses of abundance metrics were not as strongly affected by taxonomic resolution, but were strongly affected by subsample size. Data from disparate sources need to be harmonized to lowest common taxonomic level and resampled to a common subsample size prior to combining data for analysis. Failure to harmonize data sources can obscure responses to flow alteration and introduce methodological gradients that can lead to misinterpretation of responses.

Thomas Cuffney (Primary Presenter/Author), U.S. Geological Survey, South Atlantic Water Science Center, 3916 Sunset Ridge Rd., Raleigh, NC 27607, tcuffney@usgs.gov;


Jonathan Kennen ( Co-Presenter/Co-Author), U.S. Geological Survey, New Jersey Water Science Center, 3450 Princeton Pike, Suite 110, Lawrenceville, NJ 08648, jgkennen@usgs.gov;


Presentation:
This presentation has not yet been uploaded.

10:45 - 11:00: / 314 FROM GAGED TO UNGAGED: LINKING HYDROLOGIC ALTERATIONS TO BIOLOGY

5/25/2016  |   10:45 - 11:00   |  314

FROM GAGED TO UNGAGED: LINKING HYDROLOGIC ALTERATIONS TO BIOLOGY Modern management needs, such as water supply, quality, and ecosystem protection place numerous demands on instream flows. Establishing numeric flow targets may ensure maintenance of flow patterns that protect biological resources, but requires an understanding of flow-ecology relationships. This understanding is constrained by the number of gaged locations that have reliable flow information, and often these gages are located in non-representative areas. These flow ecology relationships can be strengthened by including non-gaged sites that are representative of biology. It is impractical to develop detailed models for all stream reaches where flow alteration needs to be evaluated. We developed a library of mechanistic models to estimate flows and hydrologic alterations at 700+ ungaged sites in Southern California and validated their performance under historical and present-day conditions. These models provide a large dataset to analyze relationships between instream biological condition and hydrologic disturbance. These models will permit development of flow targets that support healthy streams.

Ashmita Sengupta (Primary Presenter/Author), Southern California Coastal Water Research Project, ashmitas@sccwrp.org;


Kenneth McCune ( Co-Presenter/Co-Author), Southern California Coastal Water Research Project, kennym@sccwrp.org;


Raphael Mazor ( Co-Presenter/Co-Author), Southern California Coastal Water Research Project, raphaelm@sccwrp.org;


Eric Stein ( Co-Presenter/Co-Author), Southern California Coastal Water Research Project, erics@sccwrp.org;


Brian Bledsoe ( Co-Presenter/Co-Author), Colorado State University, brian.bledsoe@colostate.edu;


Stephen Adams ( Co-Presenter/Co-Author), Colorado State University, skadams89@gmail.com;


Christopher Konrad ( Co-Presenter/Co-Author), USGS, cpkonrad@usgs.gov;


Jason May ( Co-Presenter/Co-Author), USGS, jasonmay@usgs.gov;


Presentation:
This presentation has not yet been uploaded.

11:00 - 11:15: / 314 TRENDS IN FLOW ALTERATION OF CALIFORNIA’S RIVERS AND STREAMS (1950-PRESENT)

5/25/2016  |   11:00 - 11:15   |  314

TRENDS IN FLOW ALTERATION OF CALIFORNIA’S RIVERS AND STREAMS (1950-PRESENT) Understanding natural temporal variation is critical to assessments of streamflow alteration. We reconstructed natural monthly flows from 1950-present using statistical models that were developed using streamflow, watershed attributes, and antecedent precipitation data from 163 undeveloped watersheds in California. These models were applied to precipitation data and watershed attributes for 304 stream-gaging sites influenced by human activities. We parameterized the time series of observed / estimated natural streamflows at each site, including slope, frequency of depleted (observed < natural) and inflated (observed > natural) flows, and the presence and timing of step changes. Sites were then clustered on these parameters. Four groups emerged, each having distinct patterns in the temporal dynamics of streamflow alteration. A group of urbanized watersheds included streams with frequently inflated streamflows during the dry season (September), increasing trend in observed/natural flows, and a significant step change. Another group of watersheds with storage reservoirs also had inflated September streamflows but lacked step changes and monotonic trends. Our results suggest that natural flow reconstruction provides valuable insight into the ways in which streamflows are influenced by human activities.

Daren Carlisle (Primary Presenter/Author), U.S. Geological Survey, dcarlisle@usgs.gov;


David Wolock ( Co-Presenter/Co-Author), U.S. Geological Survey, dwolock@usgs.gov;


Presentation:
This presentation has not yet been uploaded.

11:15 - 11:30: / 314 FUNCTIONAL FLOW NEEDS FOR CONSERVATION TARGETS IN THE CENTRAL VALLEY OF CALIFORNIA

5/25/2016  |   11:15 - 11:30   |  314

FUNCTIONAL FLOW NEEDS FOR CONSERVATION TARGETS IN THE CENTRAL VALLEY OF CALIFORNIA Transformation of California’s Central Valley into an intensively cultivated landscape has required a water capture and delivery infrastructure that has severely limited the freshwater available for natural communities. Current patterns of water flows and availability are dramatically different than those under which native aquatic communities evolved. In many watersheds the water volume has not changed over time, but the magnitude, timing and patterns of flow have. To balance the water needs of ecosystems, wildlife, and people requires strategies that are specific about when and where water is needed most for our conservation targets. To inform our freshwater conservation strategies, we conducted a Freshwater Needs Assessment for California’s Central Valley. Our overarching question was how much water is needed at specific times and places to conserve aquatic ecosystems and supply water for wildlife-friendly agriculture and wetlands? We used stream flow models, combined with empirical stream flow gage data, to quantify current flow conditions and assess these relative to the flow related habitat requirements of a suite of focal species. We identify a limited set of key flow-related parameters that are most important for supporting diverse riverine communities.

Jeanette Howard (Primary Presenter/Author), The Nature Conservancy, jeanette_howard@tnc.org;


Presentation:
This presentation has not yet been uploaded.

11:30 - 11:45: / 314 DESIGNING MULTI-YEAR ENVIRONMENTAL FLOW REGIMES TO BENEFIT NATIVE FISHES AND DETER NONNATIVE FISHES DURING TIMES OF WATER SCARCITY

5/25/2016  |   11:30 - 11:45   |  314

DESIGNING MULTI-YEAR ENVIRONMENTAL FLOW REGIMES TO BENEFIT NATIVE FISHES AND DETER NONNATIVE FISHES DURING TIMES OF WATER SCARCITY More frequent and severe droughts due to rapidly changing climate are poised to exacerbate conflicts over allocating water for human use versus delivering environmental flows to benefit ecosystem functions. Despite this, quantitative models that explicitly account for the needs of multiple users remain scarce. To meet the challenges of ecologically-sustainable water management, we use multi-objective optimization to quantify the tradeoffs among allocating water for: (1) human use, (2) benefiting native fishes, and (3) inhibiting nonnative fishes; given finite and changing water availability due to climate change. Using the San Juan River Basin as a case study, we present multi-year environmental flow designs that simultaneously benefit native fishes, deter nonnative fishes, and meet human water demand, even in years of water scarcity. Reducing human water use in dry years can confer even further benefits to native fishes and disadvantages to nonnative fishes. Our results highlight the encouraging possibilities of designing environmental flows that minimize the conflicts between delivering water for humans versus ecosystems that will inevitably arise in a rapidly changing climate.

William Chen (Primary Presenter/Author), University of Washington, wchen16@uw.edu;


Julian Olden ( Co-Presenter/Co-Author), University of Washington, olden@uw.edu;


Presentation:
This presentation has not yet been uploaded.

11:45 - 12:00: / 314 USING CONDITIONAL PROBABILITY NETWORK MODELS TO OPTIMIZE ENVIRONMENTAL FLOW RELEASES

5/25/2016  |   11:45 - 12:00   |  314

USING CONDITIONAL PROBABILITY NETWORK MODELS TO OPTIMIZE ENVIRONMENTAL FLOW RELEASES Around the world, environmental water managers are being asked to ‘do more with less’ when allocating environmental water. Irrigated agriculture has long made use of numerical optimization to allocate water for best economic return on investment. In contrast, environmental water management decisions are currently based on managers’ accumulated experience along with expert inputs. We report on a project underway to develop an optimization-based decision-support tool to allocate environmental water to achieve maximal ecological benefits. We are using conditional probability networks, of the type that underpin Bayesian Networks, to parameterize simple conceptual models of how priority ecological endpoints respond to changes in flow regime. These models retain the simplicity necessary to allow solving of the optimization model, but provide an explicit representation of the dominant drivers of ecological responses that can be readily updated as new knowledge accrues. We believe this approach has great potential to drive a new wave in the development of ‘ecological demand functions’ for incorporation into the water resource models that are used to decide flow regimes in regulated rivers around the world.

Avril Horne (Primary Presenter/Author), The University of Melbourne, avril.horne@unimelb.edu.au;


Presentation:
This presentation has not yet been uploaded.