aqatic exam.docx

Strahler stream ordering

An approach to classifying streams based on their hierarchy and complexity, often correlated with stream discharge.

Stream discharge

The volume of water flowing in a river at a given time, influenced by precipitation, seasonal changes, watershed characteristics, and human activities.

Meandering river

A river channel characterized by curves and bends, typically found in low-slope areas with fine sediments.

Anastomosing river

A river with multiple semi-permanent channels that is generally characterized by lower discharge and slope.

Braided river

A river with many temporary channels created by frequent changes in flow and high sediment load, often found in steep terrains.

Hydrograph

A graph that shows how a river's discharge changes over time, typically in response to rainfall events.

Flow duration curve

A graph depicting discharge against the percentage of time flow is equaled or exceeded, used for water management.

Dynamic equilibrium in rivers

A state where inputs and outputs of a river system balance, maintaining stability despite constant changes.

Flow regime

The pattern of streamflow variation over time, influenced by natural and human factors.

Functional feeding groups

Categories of organisms in aquatic ecosystems based on their feeding behavior, which include shredders, collectors, scrapers, predators, and detritivores.

Periphyton

A community of microorganisms, including algae and bacteria, that grows on submerged surfaces in aquatic systems.

River Continuum Concept (RCC)

A model describing the predictable changes in river ecosystems from headwaters to river mouth.

Flood Pulse Concept (FPC)

A model that emphasizes the importance of seasonal flooding in supporting productivity and biodiversity in floodplain rivers.

Serial Discontinuity Concept (SDC)

A model discussing how human-made barriers, like dams, disrupt the natural connectivity and ecological processes of rivers.

Network Dynamics Hypothesis (NDH)

A model focusing on the branching structure of rivers and its effects on species distribution and ecological interactions.

Dams

Structures built across rivers to control flow, generate hydroelectric power, and provide water storage.

Levees

Embankments built along riverbanks to prevent floodwaters from inundating surrounding land.

Hydraulic action

The process by which flowing water exerts pressure and dislodges sediments from riverbanks and bed.

Eutrophication

An excessive accumulation of nutrients in water bodies, often leading to algal blooms and decreased oxygen levels.

Community structure

The composition and arrangement of different species and populations within an ecological community.