Quiz 1,Chapters 1-3

Floodplain surfaces are reshaped by what factors? Flood frequency, extent, and duration, which are modified in large part by the operation of dams,levees, and drainage systems.

How is seasonality driven in different temperate regions, such as in the Mediterranean region or more northern areas?

What has been the focus of floodplain research conducted by engineers, particularly in relation to hydrology?

What are some of the processes that can build and rework floodplains?

Why are floodplains prime sites for farms and cities?

Why are all temperate floodplains generally applicable to having novel ecosystems? Virtually all temperate floodplains are modified and/or regulated.

Why does delineating a 100-year floodplain involve considerable uncertainty?

What types of construction projects follow floods in industrialized countries?

How does climate change impact floodplains?

How can reconciliation ecology help in the restoration and management of floodplains?

What are the two most common hard engineering structures that have altered natural floodplain and riverine environments?

What is a hydraulic floodplain?

What is one effect of disconnecting a river from its floodplain due to levees? It increases channel incision, leading to faster water movement and reduced habitat for aquatic organisms.

What is hyporheic flow? Shallow groundwater flow beneath the floodplain.

What is spatial variability on floodplains? Hydrological patterns and changes that vary across floodplains based on water sources, topography, and vegetation patterns.

What role does residence time play in floodplain productivity? Longer residence allows for greater nutrient processing, sediment deposition, and productivity.

What factors influence the residence time of water on a floodplain? Floodplain topography, the magnitude and velocity of the flood wave, the slope of the valley or channel, vegetation that slows water movement, and surface and subsurface connections

How does increased flow magnitude impact floodplain water bodies? Flow pulses can reinitiate flow in side channels or abandoned braids and, by raising the water table, increase the depth and surface area of floodplain water bodies.

What is the relationship between flow frequency and flow magnitude? They have an inverse relationship, small flows occur more frequently than large floods.

What is the difference between residence time and flood duration? Duration refers to the period that a flood occurs while residence time refers to the water particles spending time on the floodplain.

What is baseflow? The low flow water remaining in the channels between storms.

What is the difference between flow magnitude and flow stage? Magnitude is the volume of water per unit time while stage is the water surface elevation (usually regarding a datum).

How can the presence of a floodplain influence the conditions within the river channel? Overbank flow onto the floodplain limits the stage of the river in the channel which limits the shear stress exerted on the on the channel bed and banks.

Which type of connectivity is often required to restore a floodplain ecosystem? Lateral connectivity: reestablishing lateral connectivity with main channels and floodplains will facilitate the flow of water, sediment, and organisms.

What is the role of hydrology in floodplain ecosystems? Hydrology shapes floodplains by driving water flow, nutrient cycling, and habitat diversity through connectivity, timing, and flow regimes.

What is temporal variability? The hydrologic variability of various events such as single storms and climate patterns across a range of timescales (annually, seasonal, decadal, etc.)

Give examples of how residence time of water influences floodplain ecosystems. Water quality(turbidity), Biogeochemical processes (water or nutrient cycles), Ecological processes (natural-interactions in ecosystems) .

How can sediment deposition in floodplains improve water quality? decreases a river’s suspended sediment load

How are splay deposits formed? When the river breaches a levee and laterally deposits sediments over the floodplain.

What is one of the primary processes for building floodplain surfaces in meandering rivers? Lateral accretion

What is the term for the body of water that is the result of neck and chute cutoffs? Oxbow lakes

What type of river forms an oxbow lake and how? A meandering river continues to meander/migrate until the connecting land of two bends erodes away forming an oxbow lake.

Stream power is the product of what three values? the channel discharge (Q), the channel slope (downstream gradient), and the specific weight of water.

What is sinuosity? A measure of the curviness of a river, a ratio found by dividing the length of the channel centerline by the straight-line distance between the same 2 points.

What influences sediment deposition during overbank flooding? Vegetation, sediment size, and topography

Lateral accretion refers to the deposition of sediments on point bars; what are point bars? Sediment deposits that form on the inside bend of a river.

Name one single-channel pattern and one multiple-channel pattern of lowland rivers. Single: straight, sinuous, meandering; Multiple: braided, anastomosing.

Do rivers typically deposit their coarsest or finest sediment load immediately adjacent to the channel during overbank flow? Coarsest

What causes an avulsion to occur? Rivers can change course and form new channels through blockage of the original flow direction by build up of material from beaver damns, driftwood, and sediment deposition.

How does sediment accumulation modify nutrient transport in rivers? Phosphorus is removed from the river waters.