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Home My WebLink AboutBiofidelity_Analysis_(RTI)RTI International RTI International is a trade name of Research Triangle Institute.www.rti.org Biological Fidelity Analysis of Stream Classes - UPDATE Funded by: Environmental Defense Fund Conducted by: RTI International RTI International Project Objectives: To adopt a stream classification system that represents the distribution of aquatic biota in North Carolina –Compare fidelities of aquatic biota to different stream classification systems Environmental Flow Specialists (EFS) McManamay et al., 2011 (McManamay) –Adopt the most suitable classification system and/or modify a system to better reflect biological assemblages RTI International Project 7 Steps 1.Determine catchments to include in analysis: –minimally altered water quality and flow condition –1,094 NHD+ catchments 2.Link catchments with biological data: –benthos – 1,094 –fish – 416 3.Conduct preliminary statistical analysis of biological fidelity to test analysis framework: –106 catchments –individual species and community analyses RTI International Project 7 Steps 4.Compare stream classification systems: –EFS and McManamay RTI International Stream Classification Systems EFS: –Developed for NC –Developed using USGS gage data restricted to locations with “stable flow conditions”for 18+ years (185 gages) –Based on 22 ecologically-relevant flow metrics –7 classes: B - Small Stable Streams A - Coastal Streams F - Medium Stable Streams E - Large Piedmont Rivers C - Large Stable Streams D - Small Flashy G - Small Seasonal RTI International Stream Classification Systems McManamay: –Developed for Southeastern U.S. (8 states) –Developed using USGS gage data restricted to catchments with minimally disturbed, “unregulated”stream condition (292 gages) –Based on 9 ecologically-relevant flow metrics in hydrologic classification tree –8 classes (6 main classes): IF - Intermediate Flashy SBF1 - Stable High Baseflow 1 CSI - Coastal Swamp/Intermittent SBF2 - Stable High Baseflow 2 BKR - Black River PR1 - Perennial Runoff 1 UPR - Unpredictable Perennial Runoff PR1 - Perennial Runoff 2 RTI International Project 7 Steps 4.Compare stream classification systems: –EFS and McManamay –classifications determined using USGS gage data –147 catchments (restricted to catchments with 15+ years of USGS records between 1960 – 2006) RTI International Comparison of Stream Classification Systems Kappa statistic = -0.145 Conclusion: classifications are dissimilar enough that biological fidelity analyses should be conducted on both systems Classes A B C D E F G McMan Sum CSI 12120000 15 IF 00018001 19 PR1 3203001 9 PR2 5120181 1 0 37 SBF1 01011020 14 SBF2 133122 0 5 0 53 EFS Sum 21 58 15 42 1 8 2 147 RTI International Project 7 Steps 4.Compare stream classification systems: –EFS and McManamay –classifications determined using USGS gage data –147 catchments (restricted to catchments with 15+ years of records between 1960 – 2006) –CONCLUSION = classifications are not the same 5.Compare stream classes determined using USGS gage and WaterFALL hydrology data: –EFS and McManamay –147 catchments RTI International EFS classification – comparison of USGS and WaterFALL data sources EFS Class % USGS – WaterFALL Match B - Small Stable 93% (54/58) C - Large Stable 67% (10/15) F - Medium Stable 25% (2/8) D - Small Flashy 10% (4/42) A - Coastal 10% (2/21) G - Intermittent 0% (0/2) E - Piedmont River 0% (0/1) Total 49% (72/147) Only 49% match Stable streams (B, F and C) are sensitive to the median base flow metric Flashy streams (D and A) are sensitive to the Very High Flows ( >90th percentile) metric RTI International RTI International McManamay classification – comparison of USGS and WaterFALL data sources McManamay Class % USGS – WaterFALL Match SBF2 89% (47/53) PR2 73% (27/37) CSI 53% (8/15) SBF1 43% (6/14) PR1 22% (2/9) IF 21% (4/19) Total 64% (94/147) Only 64% match Thresholds of classes sensitive McManamay found classification tree resulted in 66- 80% accuracy in assigning USGS gages to classes RTI International RTI International McManamay classification – comparison of USGS and WaterFALL data sources Combined classes: Stable Base Flow (SBF1 + SBF2) Perennial Run Off (PR1 + PR2) Increased to 76% match Grouped McManamay Class % USGS – WaterFALL Match SBF 99% (66/67) PR 72% (33/46) CSI 53% (8/15) IF 21% (4/19) Total 76% (111/147) RTI International Project 7 Steps 4.Compare stream classification systems: –EFS and McManamay –classifications determined using USGS gage data –147 catchments (restricted to catchments with 15+ years of records between 1960 – 2006) –CONCLUSION = classifications are not the same 5.Compare stream classes determined using USGS and WaterFALL hydrology data: –EFS and McManamay –147 catchments –CONCLUSION = can’t extrapolate either classification beyond USGS gages RTI International Project 7 Steps 6.Assign stream classes to all 1,094 catchments 7.Conduct biological fidelity analyses to determine fidelities of benthos and fish to the stream classes RTI International What’s Next? Need a classification system that is: –Not based on sensitive threshold values –Consistent and reproducible using USGS stream gage and modeled data –Easy to understand and implement –Can be applied throughout state –Captures the distribution of aquatic biota in North Carolina NCDENR is in process of evaluating other potential approaches –balance of Biological Fidelity project will be devoted to pursuing an alternative approach RTI International Questions?