3.
Definition and classification of pressure information within four groups: hydrology (H), morphology (M), water quality (W) and connectivity (C)
| Pressure variable | Group | Code | Explanation; short description of classes | Examples of effects |
|---|---|---|---|---|
| Impoundment | HPI | H_imp | Natural flow velocity reduction on site because of impoundment; 1 = no (no impoundment), 3 = weak, 5 = strong | Reid (2004) |
| Hydropeaking | HPI | H_hydrop | Site affected by hydropeaking; 1 = no (no hydropeaking), 3 = partial, 3 = yes | Flodmark et al. (2004); Scruton et al. (2008) |
| Water abstraction | HPI | H_waterabstr | Site affected by water flow alteration/minimum flow; 1 = no (no water abstraction), 3 = weak to medium (less than half of the mean annual flow), 5 = strong (more than half of mean annual flow) | Reid (2004)); Thorstad et al. (2008); Benejam et al. (2009) |
| Reservoir flushing | HPI | H_resflush | Fish fauna affected by flushing of reservoirs upstream of site; 1 = no, 3 = yes | Bash & Berman (2001); Crosa et al. (2010) |
| Hydrograph modification | HPI | H_hydromod | Seasonal hydrograph modification because of hydrological alteration (water storage for irrigation, hydropower etc.); 1 = no, 3 = yes | Jackson & Marmulla (2000); Roy et al. (2005) |
| Channelisationa | MPI | M_channel | Alteration of natural morphological channel plan form; 1 = no, 3 = intermediate, 5 = straightened | Raat (2001); Aarts et al. (2004); Muhar et al. (2008) |
| Cross-sectiona | MPI | M_crosssec | Alteration of cross-section; 1 = no, 3 = intermediate, 5 = technical crossec./U-profile | Bravard et al. (1997); Raat (2001); Muhar et al. (2008) |
| Instream habitata | MPI | M_instrhab | Alteration of instream habitat conditions; 1 = no, 3 = intermediate, 5 = high | Muhar et al. (2008) |
| Embankment | MPI | M_embankm | Artificial embankment; 1 = no (natural status), 2 = slight (local presence of artificial material for embankment), 3 = intermediate (continuous embankment but permeable), 5 = high (continuous, no permeability) | Neumann (2002), Wolter (2008) |
| Flood protection | MPI | M_floodpr | Presence of dykes for flood protection; 1 = no, 3 = yes | Tockner et al. (1998); deLeeuw et al. (2007) |
| Barriers segment upstream | CPI | C_B_s_up | Barriers on segment level upstream; 1 = no, 3 = partial, 3 = yes | Rieman & Dunham (2000); Zitek et al. (2008) |
| Barriers segment downstream | CPI | C_B_s_do | Barriers on segment level downstream; 1 = no, 4 = partial, 4 = yes | Rieman & Dunham (2000); Zitek et al. (2008) |
| Acidification | WQPI | W_acid | Acifidication; 1 = no, 3 = yes | Sandin & Johnson (2000); Leduc et al. (2008) |
| Eutrophication | WQPI | W_eutroph | Artificial eutrophication; 1 = no, 3 = low, 4 = intermediate (occurrence of green algae), 5 = extreme (oxygen depletion) | Sandin & Johnson (2000); Smith et al. (2006) |
| Organic pollution | WQPI | W_opoll | Is organic pollution observed; 1 = no, 3 = weak, 5 = strong | Penczak & Kruk (1999); Nilsson & Malm Renöfält (2008) |
a
Original variables M_channel, M_instrhab and M_crossec aggregated to M_morph_instr.