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HomeMy WebLinkAboutRTI_WaterFALL_RTI International RTI International is a trade name of Research Triangle Institute. www.rti.org WaterFALL Status 11/27/12 Michele Cutrofello Eddy RTI International Where we are….and where we’re going Current ecological flow work for EDF –Mostly focused in NC –Assessing the hydrology and biology –Focus on locations with biological monitoring data Current resilience study for TNC –Assessing changes in flow metrics and baseflow contributions to flow as two components of a resiliency study for NC –Summarizing results to HUC12 and HUC8 levels Current development of a hydrologic foundation for the southeast U.S. for SALCC Beginning freshwater assessment pilot study for Louisiana for TNC RTI International •Catchments average 1.7 km2 in NC modeled area •58,187 modeled catchments across 21 watersheds •Summarized to 1285 HUC12s •Total modeled area: 100,000 km2 or 38,700 mi2 RTI International RTI International Calibration Notes Variety of performance metrics evaluated –Volume error over daily flows (#) – automated calibration –Nash-Sutcliffe Efficiency for daily flows (#) –Daily hydrograph (visual) –Flow duration curves (visual) –Monthly median and mean volumes (visual & #) –Ecoflow Metrics (#) General findings –No one area or stream type consistently out-performed others –Residuals/errors scattered; no consistent bias (that’s good!) –Comparisons between WaterFALL and other rainfall-runoff models for prediction of ecoflow metrics are promising RTI International Daily Hydrographs Check for general patterns and trends Storm peaks and recessions Order of magnitude agreement Example hydrograph from the Chattahoochee River gage near Cornelia, GA (stable stream) Example hydrograph from the Meherrin River gage near Lawrenceville, VA (perennial stream) RTI International Flow Duration Curves Examine high, median, and low flow representations by WaterFALL Check for behavior and magnitude Flow duration curve (calibration period) for Chattooga River near Clayton, GA (SBF) Flow duration curve (calibration period) for Falling River near Naruna, VA (PR) RTI International Monthly Flows Check for seasonality/ patterns Seasonal bias? Median monthly flow comparison (calibration period) for Alcovy River above Covington, GA Median monthly flow for the Tick Creek Gage (Cape Fear Basin) RTI International RTI International Ecoflow Metrics – RTI’s Percentile Version RTI International Ecoflow Metric Estimation Across Classes RTI International “Coloring In” the State with Stream Classes RTI International Mayo Creek “Sphere of Influence” Example RTI International Mayo Creek “Sphere of Influence” Example RTI International Mayo Creek: Pre- and Post-Alteration RTI International Monthly Flows at Three Points Along River At Dam 25 km Downstream Ex t r e m e L o w F l o w s Hi g h F l o w s Me d i a n F l o w s Unreg: PR Reg: CSI Unreg: PR Reg: PR Unreg: PR Reg: PR 8 km Downstream RTI International Persistence of Alterations Downstream RTI International Interpreting Hydrologic Metrics for Ecological Flow Development What metrics are important to the biology? –Consider life cycles, flow requirements, migration…. Define the “sphere of influence”. How far downstream do the impacts persist? –Is the distance over which the impacts persist acceptable given perceived benefit of the alteration? –Does this distance drastically change based on hydrologic regime and/or some ratio of drainage area and alteration? Can thresholds be determined based on these characteristics? Are certain seasons more impacted than others? –Can regulations be set by season or month? Are effects more prevalent at different points of the flow regime? –Leads to the actual metric that will be used in setting regulations or guidelines RTI International Stay tuned….. Michele Cutrofello Eddy Environmental Engineer 919.990.8458 mcutrofello@rti.org (for now) RTI’s WaterFALL™ https://waterfall.rti.org