lec 2 Flashcards
what is a catchment/watershed?
what counts for a catchment: surface water? groundwater?
river that feeds into a larger body of water
defined on surface water, NOT ground water
contrast pools and fluxes? there are two fluxes in the following list. identify them.
- lake
- river
- runoff
- snowpack
- rain
- atmosphere
- groundwater
pools are bodies where water stays for a long time, whereas fluxes are spaces where water is transient
lake: P
river: P
runoff: F
snowpack: P
rain: F
atmosphere: P
groundwater: P
explain the soil profile (5 parts). how does it influence freshwater ecology?
O: organic matter
A: surface
B: subsoil
C: substratum
R: bedrock
O feeds into A, while R feeds into C; B is where A and C mix
this matters bc runoffs typically affect O layer (or conversely, the O layer affects the runoff)
how do catchments in remote areas compare to catchments in agricultural areas? what does this mean for the implications of anthropological impact on freshwater?
study of northeastern streams in US found that N inputs were dropping in forests, while N was being injected into streams in agricultural areas
ie we’re fucking everything up
compare/contrast lentic and lotic systems
lotic: moving w unidirectional flow
lentic: still waterbodies lacking unidirectional flow
realistically lotic - lentic exists in spectrum, not binary
how do ponds differ from lakes? what about wetlands?
- shallow enough that light reaches bottom
- pond freezes all the way through (not helpful metric for warmer climates)
- typically defined as <2 ha in size
wetlands are shallow and dominated by aquatic vegetation
define oligotrophic + eutrophic lakes. what causes a lake to move across the spectrum bw the two?
oligotrophic: low nutrient level = low prim prod
eutrophic: high nutrient level = high prim prod
lakes capture sediment, which in turn captures nutrients
what is a dystrophic lake? what causes them to arise?
hella organic matter in there, from catchment picking up debris + sediment and depositing it in lake
- cloudy + usually brown coloured
what is a caldera? does it tend more toward oligotrophic or eutrophic?
calderas are volcanic basins that fill w water. super large + deep. catchments are significantly smaller than the body they feed; few means for nutrients to enter the caldera (low prim prod).
what is an oxbow lake? does it tend more toward oligotrophic or eutrophic?
meandering rivers have faster flow on the outside and deposition on the inside (see notes for picture). as the deposition moves inward and the flow moves outward, the river may cut off and form a new river, leaving the cut off part behind. tends more towards eutrophic but its not algal bloom levels.
what are kettle/pothole lakes? are they glacial water or no?
as glaciers receded, some ice got left behind in ridges called tills, which eventually melted and formed lakes. while they WERE glacial waters at some point, they are now participating in the water cycle all on their own.
what is a reservoir?
man made lake. tend to have lots of decomp since catchments feed into it. [CHECK THIS IDK!!]
