Methods/tools that can be used to assess ecological flow requirements in rivers with varying degrees of hydrological alteration and instream values.
Degree of hydrological alteration |
Significance of instream values |
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Low |
Medium |
High |
|
Low |
Hydrological rule-of-thumb (e.g. see MALF and flow duration curves in NZRiverMaps) Wetted aquatic habitat (e.g., see Wetted width in NZRiverMaps) Expert Panel |
Historical flow method (e.g., see MALF, flow duration curves & FRE3 in NZRiverMaps, Indicators of Hydrological Alteration) Expert Panel |
Cultural flow assessment (e.g., COMAR) Generalised fish habitat modelling (e.g., CHES) 1-D hydraulic habitat modelling (e.g., RHYHABSIM) Connectivity/fish passage (e.g., Bespoke analysis) Flow duration analysis (e.g., see flow duration curves in NZRiverMaps, Indicators of Hydrological Alteration) |
Medium |
Historical flow (e.g., see MALF, flow duration curves & FRE3 in NZRiverMaps, Indicators of Hydrological Alteration) Expert Panel Generalised fish habitat modelling (e.g., EFSAP) |
Generalised fish habitat modelling (e.g., EFSAP, WAIORA) 1-D hydraulic habitat modelling (e.g., RHYHABSIM) Connectivity/fish passage (e.g., Bespoke analysis) |
Cultural flow assessment (e.g., COMAR) 1-D hydraulic habitat modelling (e.g., RHYHABSIM) 2-D hydraulic habitat model Dissolved oxygen model (e.g., WAIORA ) Temperature models (e.g., WAIORA) Suspended sediment Fish bioenergetics model (e.g., NREI;) Groundwater model (e.g., see National Hydrological Project) Connectivity/fish passage (e.g., Bespoke analysis) Flow variability analysis (e.g., Indicators of Hydrological Alteration) Deposited fine sediment (e.g., Haddadachi et al. 2017) |
High |
Generalised fish habitat modelling (e.g., CHES) 1-D hydraulic habitat modelling (e.g., RHYHABSIM) Connectivity/fish passage (e.g., Bespoke analysis) Generalised periphyton biomass model (see Snelder et al. 2013) |
Cultural flow assessment (e.g., COMAR) Entrainment model 1-D hydraulic habitat modelling (e.g., RHYHABSIM) 2-D hydraulic habitat model (e.g., Delft2D + RHYHABSIM) 2-D periphyton & invert model (e.g., Delft2D + DELWAQ) Bank stability Dissolved oxygen (DO) model (e.g., WAIORA, multi-station DO model) Temperature models (e.g., WAIORA) Suspended sediment (e.g., see Hicks et al. 2011 model in NZRiverMaps) Fish bioenergetics model (e.g., NREI) Inundation modelling (e.g., see Smart & Lane) Groundwater model (e.g., see National Hydrological Project) Connectivity/fish passage (e.g., Bespoke analysis) Periphyton biomass model (e.g., see Hoyle et al. 2017) Deposited fine sediment (e.g., Bespoke analysis) Also, where instream values are high: Flow intermittence (e.g., ELFMOD) Flow variability analysis (e.g., Indicators of Hydrological Alteration) |