2. The Origin of Lakes Flashcards
In North America, catchment and watershed are typically used interchangeably to refer to:
the entire land surface that drains hydrologically into a waterbody
In Europe, what does watershed refer to?
the uppermost boundary (borderline) from which water can drain into a catchment
T/F
Groundwater flow and surface flow cannot have different patterns in the same location
false
Groundwater flow can follow the pattern for surface water, but it can also have subsurface flow patterns that are different because of subterranean geology
The water cycle exists as a series of pools and fluxes.
Pools=
Fluxes=
Pools=
- lakes
- rivers
- snowpack
- groundwater
- ocean
- atmosphere
Fluxes=
- evapotranspiration
- runoff (rivers)
- precipitation
What are the soil horizons?
O (Organic)
A (surface)
B (subsoil)
C (substratum)
R (Bedrock)
Lakes and rivers integrate the landscapes over __(broad/narrow) spatial scales
broad
Aquatic ecosystems reflect the condition of the surrounding _____
landscape!
List some aspects of the surrounding landscape that could impact aquatic ecosystems
- vegetation
- roads
- urbanization
- dams
- agriculture
These affect the chemistry and biology of receiving waters
Lotic systems=
moving water bodies having unidirectional water flow
Lentic systems=
still waterbodies lacking unidirectional water flow
Give examples of lotic vs lentic systems
lotic= creeks, streams, rivers
lentic= lakes, ponds, reservoirs, wetlands
Wetlands=
shallow (<1m deep) waterbodies dominated by aquatic vegetation throughout
T/F
There is no universal definition to differentiate ponds and lakes
true!
just ponds are smaller than lakes
Give 3 possible definitions to differentiate ponds and lakes
- ponds are shallow enough that the bottom gets light (light through whole water column)
- Ponds freeze to the bottom (bad definition for warm climates)
- ponds are less than 2 hectares in area
What is the emerging definition of a pond given by Richardson et al. 2022?
Ponds= waterbodies that are small (less than 5 hectares), shallow (less than 5m), with less than 30% emergent vegetation
T/F
Ponds and lakes function very similarly/ the same
false
small waterbodies function quite differently compared to a midsize-big lake
Oligotrophic lakes=
Lakes with low primary production as a result of low nutrient (N,P) levels
Eutrophic Lakes=
Lakes with high primary production as a result of high nutrient (N,P) levels’ potentially to the point where ecosystem function declines (eutrophication)
Dystrophic Lakes=
aka:
aka “bog lakes”
= lakes with significant inputs of organic matter; this enables respiration to exceed photosynthesis
- shading by organic matter inhibits light penetration
______ are volcanic lakes. Are they deep or shallow?
Calderas
very deep
How does an oxbow lake form? Are they relatively shallow or deep?
They are a cutoff of a meander in a meandering river
Relatively shallow
How do kettle lakes (prairie potholes) form?
At the base of a glacier, chunks of “dead ice” get buried by outwash. Eventually they melt, and the outwash erodes away and you’re left with kettle lakes
T/F
Lake origin is an important determinant of lake function
true
