Rivers

Question 1

Rivers

Answer 1

loting (flowing) environments which are confined by a riverbed but receive water from a large are (catchment, watershed, river basin)
can from different channel geometries (straight, meanderung, braided)
streams are clearer, smaller and consist of shallow gravel riffles and pool collecting debris

Question 2

types of streams

Answer 2

Ephemeral stream (only a short period during a rainy period9

Intermeittent strems (flow at differen times of the year or seasonally (glacier runoff))

Perennial streams (all year round)

Question 3

Physical parameters

Answer 3

gradient
Cross section
discharge
velocity
underlying geology
Riparian vegetation

Question 4

Fish zonation

Answer 4

Trout zone
Gayling zone
Barbal zone
Bream zone

Question 5

Trout zone

Answer 5

steep gradient
fast flowing cool water
water well oxygenated due to turbulences
fishes lay adhesive eggs
characteristic species include bronw trout and stone loach

Question 6

Grayling zone

Answer 6

temperature slightly higher
still adhesive aggs
species: Greyling, chub

Question 7

Barbel zon

Answer 7

essentially lowland with uplang river characteristics
gentle gradient moderate flow
plants can take root
fish lay their eggs in the vegetation
species: Barbel, Pike

Question 8

Bream zone

Answer 8

lowland zone
slow flow and gentle gradient
more variable in temperature
most upland species cannot survive here
adhesive eggs in weeds
species: Bream, Carp

Question 9

River continuum concept

Answer 9

Model for describing and classificing flowing water
how wnergy flow change with the stream oder
based on the concept of dynamic equilibrium in which the river froms a balance between all its physical parameters
over major sections of a river, communities develop which can achieve equilibrium with the physical feature of the river

Question 10

First order

Answer 10

only input is runoff, large amount of nurtients because of fallen leaves

Question 11

Headwaters (order 1 to 3)

Answer 11

Very narrow and lined by thick vegetation
majority of organic matter is allochinthonous plant material that falls into the river
low photosynthesis

Question 12

Midreaches (order 4 to 6)

Answer 12

structure like rocks and trees play a role as suppliers of organic materials
higher photosynthesis to respiration ratio

Question 13

Lower reaches (order > 6)

Answer 13

large flus of particulate material
higher water cloudiness –> less photosynthesis

Question 14

River typology

Answer 14

classifictaion of river segments based in their characteristics as potentiasl habitats

core criteria are cliate, altitude and catchment size

Question 15

basic conditions

Answer 15

geology and hydrochemisty –> immission parameters

morphology and biological conditions –> typology

Typology –> determining biological and chmeical quality

Question 16

Austria

Answer 16

Austria has 17 surface water type regions and 9 large rivers. Combining those regions with abiotic and macrozoobenthos information leads to 15 bioregions as a base for river typology. The
classification to a certain type depends on the bio-
region, the altitude, and the catchment class.

Question 17

Ecological status

Answer 17

Biological quality (fish, macrozoobenthos, …)
supporting hysio-chemical parameters (nutrients, oxygen, salinity, …)
Hydromorphological quality (slope, shape, human constructions, ….)
National relevant and river basin specific pollutants

Question 18

Biological Quality elements

Answer 18

In Austria, the ecological status is assessed as a comparison to the estimated pristine status according to the 15
bioregions in Austria. For large rivers specific water sections are defined.

Question 19

Fish

Answer 19

Life spand, life cycle and diverse habitat requirements
sensitive to changes in the morphiology and temp as well as natural extremes and machanisms interal to the population

Question 20

Fish II

Answer 20

all relevant habitats
catch and identify by electrofishing

Question 21

Macrosoobenthos

Answer 21

organic pollution (untreated wastewater)
acidification and changes in hydromorphology

Question 22

Ecological status - Macrozoobenthos

Answer 22

two step approach
rough screening: good/very good ecological status
detailed MZB method is used to further identify the exact status (consits of 3 modules)

Question 23

Saprobic status

Answer 23

Objective: provide water quality classification in terms of organic pollution (saprobity)

Principle: every species has a dependency on decomposing org. substances and thus oxygen content

Advantages: quick classification can be made on a universal scale

Question 24

Quality classes

Answer 24

SI 1 = oligosaprobic (none to very slight pollution, clear water, diverse insect fauna with few
specimen)

SI 2 = β-mesosaprobic (moderate pollution, good oxygen saturation, highly diverse insect
fauna of high abundance

SI 3 = α-mesosaprobic (heavy pollution, may be turbid, oversaturation/heavy depletion of
oxygen, few tolerant species of high abundance)

SI 4 = polysaprobic (extreme pollution, animals shaded by suspended material, extreme
oversaturation/heavy depletion of oxygen making water breathing life impossible,

Question 25

General degradation

Answer 25

Potamalisation: shift from upstream to downstream communities due to water temperature
increase

Rhitralisation: opposite effect to potamalisation due to temperature decrease

Toxic pollution

Question 26

Acidification

Answer 26

Often linked to input of aluminum -> shift to more tolerant species

Question 27

Phytobenthos (plants on riverbottom, inculdes all algae)

Answer 27

sensible to small-scale changes over short time periodes
not suitable to depict interventions in rivers

three modules to determin the status (Ecological quality ration)
Trophic status
Sapobic status
Reference species

Question 28

Trophic staus (based on trophic index)

Answer 28

Assessment of the nutrient load
deviation of the determines trohpic condition from the respective bioregion-specific reference

Question 29

Saprobic status (based on saprobic indes(

Answer 29

organic loag
shows deviation of the determined saprobic condition from the respective biogregion-specific referende

Question 30

reference species (based on reference-species index)

Answer 30

impact regarding water chmistry and hyromorphology
shows deviation of the found biotic community from the referende bioconenosis expected in the respective bioregion and altitudinal belt

Question 31

Macrophytes (plants with clear structured sprouts, like mosses or seed plants)

Answer 31

stay in the same place
longevity (integrate the surrounding conditions over a long period)
trophic status and react to changes in the flow regime and structural conditions
Analyzed in terms if species and quantity (in a representative river section)
deviation of the found species community from a type-specific range of reference species according to the waterbody type