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Normative Flow Studies. Small Streams Biology-Hydrology Analyses. Project Goals. Analytical and decision tools for managers Understand relationships : flows ecological condition Evaluate effects : management actions flows ecology. Issues/Challenges - Science.
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Normative Flow Studies Small Streams Biology-Hydrology Analyses King County DNRP/Parametrix
Project Goals • Analytical and decision tools for managers • Understand relationships: flows ecological condition • Evaluate effects: management actions flows ecology King County DNRP/Parametrix
Issues/Challenges - Science Arrows indicate relationships that are important to the technical questions at hand. The weight of the arrows indicates the degree of this project’s focus on the indicated relationship – not their overall importance or the merit of studying them in a different project. Human Actions Habitat Structure Magnitude Biology e.g., salmon conservation Frequency FlowRegime Duration Seasonality Rate of Change WaterQuality Biological Interactions Energy Flow King County DNRP/Parametrix
Several Possible Approaches…. • Indicator-based approach – inform management Conceptual Model Inform Management Actions Define Metrics to Describe System Condition Test Metrics
Metric Relationships Indicator Response Biology Metric (receptor) Hydrology Metric (Stressor)
Linking Biology and Hydrology • Watersheds with both data types • Urbanization gradient • Pair biology and hydrology • “Subbasins “ • Distinct hydrology • One or more BIBI sites • Small data set King County DNRP/Parametrix
Available Data: Hydrology • Few long term gauge records • Modeled flow data (HSPF) available for some watersheds • Developed flow for 50 years • Original forested land cover - Baseline • Current land cover (1995/1998) - Scenario • Computed metrics for both conditions • M, D, F, T, rates of change King County DNRP/Parametrix
Available Data: Biology • Macroinvertebrate data • Raw data for Benthic Index of Biotic Integrity (BIBI) • BIBI - general indicator of ecosystem integrity • Not designed to assess effects of flow • Only “calibrated” for 2nd and 4th order streams • No long term records (1995-2001 longest period) • Tested BIBI metrics plus other life history/richness metrics King County DNRP/Parametrix
Issaquah (8/35;34) Bear/Evans (19/63;51) Little Bear (5/18) Swamp (7/12;11) Madsen (2/6;2) Miller (1/0) Thornton (5/15/9) Sample size = 125 Working Biological Data Set King County DNRP/Parametrix
Example Hydrograph King County DNRP/Parametrix
Forested Rise Count vs. Current Rise Count Non-urbanized Watershed Urbanized Watershed King County DNRP/Parametrix
BIBI Score vs. Q2:Q10 in sites with similar local land cover (within 100m of BIBI site) King County DNRP/Parametrix
Canonical Discriminant Functions Annual Ratio Hydrology Metrics normalized 3.0 2.0 1.0 Function 2 0.0 BIBI group Group Centroids -1.0 35 - max -2.0 20 - 35 -3.0 min - 20 -5 -4 -3 -2 -1 0 1 2 Function 1 35 - max min - 20 20 - 35 King County DNRP/Parametrix
Uni+semi voltine taxa groups Func1: longer LPD, runoff duration, and decreased Q2:Q10, LPC, HPR, Power, FC, & reversals King County DNRP/Parametrix
Func1: increased LPD, later onset fall flows and later date annual min, & lower Q2:Q10, fewer LPC and fewer reversals King County DNRP/Parametrix
Length of High Pulse Period vs. BIBI Groups King County DNRP/Parametrix
Time (in days) Between Low Pulse Events vs. BIBI Groups King County DNRP/Parametrix
Number of Low Pulse Events/Yr vs. BIBI Groups King County DNRP/Parametrix
Ratio of current 2-yr discharge to historic 10-yr discharge vs. BIBI groups King County DNRP/Parametrix
Stream Power Q2:Q10 LP/HP counts, duration, range Onset fall flows % time above 2-yr baseflow Date minimum flow Runoff event counts Runoff event duration Reversals Potential Hydrology Indicators King County DNRP/Parametrix
Conclusions King County DNRP/Parametrix
Relationships between biology and hydrology metrics • ‘Worst’ and ‘best’ biological sites can be separated based on hydrology metrics • Life history and richness metrics significantly correlated with specific hydrology metrics • Measures of hydrologic ‘disturbance’ and biological resistance/resilience to disturbance may be most productive King County DNRP/Parametrix
Next Steps • Document analyses/report • Validate relationships with separate data set(s) • Test relationships with other biological data (e.g., fish) • Summarize findings for managers – what general guidance can be derived from preliminary analyses? King County DNRP/Parametrix