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Applying IFIM on the Gila River. Methods for recommending fishery flows. -Minimum flow, hydrograph -Natural flow regime -WUA-based, PHABSIM only -WUA-based, IFIM. Terminology. -IFIM vs. PHABSIM -Physical HABitat SIMulation vs. Instream Flow Incremental Methodology. PHABSIM.
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Methods for recommending fishery flows • -Minimum flow, hydrograph • -Natural flow regime • -WUA-based, PHABSIM only • -WUA-based, IFIM
Terminology • -IFIM vs. PHABSIM • -Physical HABitat SIMulation • vs. • Instream Flow Incremental Methodology
PHABSIM • -Study sites/transects • -Microhabitat (depth/velocity/substrate, cover) • Fish habitat suitability indices (HSI) • -WUA as a function of discharge
PHABSIM • -Mesohabitats • -Transects • -Microhabitat measurements • Depth/velocity/substrate/cover -Habitat Suitability Indices (HSI) -Weighted Usable Area (WUA)
MESOHABITATS • -Pool • -Riffle • -Cascade • -Complex habitats
CASCADE Cascade
PHABSIM • Models Weighted Usable Area (WUA) • Ends at WUA
IFIM • -A problem-solving approach • -Usually incorporates • PHABSIM • Hydrology • -Often incorporates • Temperature/water quality • Sediment • Flood flows • Special habitats
IFIM • -Can incorporate many other effects • Channel change • Predation • Competition • Migration • Food base • other
Incorporating Temperature WUA (ft/1000 ft) x Total Length 1000’s of ft) x Temperature Suitability per length = Total Habitat
IFIM: Drawbacks • Salmon and trout • WUA ~ Population? • Multi-species interpretation difficult • PHABSIM-only oversimplified • Data-intensive
IFIM: Strengths • Accepted methodology • Incorporates many disciplines • Expertise/support available • Incremental results • Allows negotiated solutions
Example issues • Is channel in equilibrium? • Water quality and temperature • Invasive species: predation/competition • Do key species migrate? • Critical habitat areas • Food base effects • Population bottlenecks • .........100 others
STUDY PLAN - 1 • 1. Describe the proposed action. • 2. Describe the issues. • 3. Identify target species/resources. • 4. Select methods to address each issue. • 5. State the study objectives.
STUDY PLAN - 2 • 6. Delineate study boundaries. • 7. Identify the baseline condition. • 8. Details, quality control - studies/models. • 9. Schedule, milestones, deadlines.