Exam 2 Flashcards
(34 cards)
API
aniticipated precipitation index
Runoff ratio
- tells us how much of the water that came from precipitation was converted into runoff
- specific discharge divided by precipitation
- can only have a high RR after a storm (greater that 1)
- typical RR is 20-30%
Antecedent moisture
- relationship between precip and stream flow
- is not measured by moisture
How is antecedent moisture measured
- measured by stream flow in the US (antecedent flow conditions)
- measured by precipitation–antecedent precip–
What is SRP
- soluble reactive phosphate
- the stuff that goes through the filiter
What is PP
- particulate phosphate
- the stuff that doesn’t go through the filter and has organic matter
Zone 3 buffer
- runoff control zone
- typically grasses
- intersects any type of overland flow entering the buffer
Zone 2 buffer
- managed forest
- 10 to 20 meters wide
Zone 1 Buffer
- undisturbed forest
- 5 to 10 meters wide
- grows good root systems to stabilize banks
- can provide organic matter and habitat to streams by falling in
Denitrification
- needs OM and nitrate, anoxic
- minneralization (occurs best in anerobic env but can work in anoxic ones)
- as OM is being oxidized (e donor), NH4+ is being created
Nitrification
- strictly aerobic (NH4+—>nitrate)
- Anoxic wetlands have high NH4+
Methylmercury in wetlands (NeHg)
- need to be in a place with atm deposition of Hg
- Hg prefers OM, wet, anoxic env
- makes wetlands a perfect spot for Hg deposition
- anoxic wetland creates sulfate reducers and produces NeHg with Hg
- NeHg is produced in high amounts in NE US
PRB
- permeable reactive barriers (bioreactors)
- remove nitrate
- needs sand/gravel, OM, water (anerobic env)
- OM helps with denitrification
- sand/gravel allows water to flow through system and OM, allowing denitrification to occur
- woods chips commonly used for N removal
what happens when ag is not tilled over time
- natural porosity comes back and allows soil to not be overly compact
- roots and worms provide OM when they die
- there is less overland flow and PP when natural porosity comes back
- reconnects the soil profile to water
- allows P to move through the soil profile, giving more SRP in subsurface flow (can lead to algal blooms)
Conventional tillage
-break down of the top layer of soil profile to maintain soil porosity
Systematic pesticide
- water that is absorbed by plants
- pesticide resides in plant tissue
Non-systematic pesticide
-on outside of plant`
TP
-total phosphorous
=SRP + PP
-SRP is generally less than 50% of TP
When are P exports the greatest
-during high flow periods and in the spring due to snowmelt
Reduction potential
-a measure of the tendency of a chemical species to acquire electrons and be reduced
Oxidation vs reduction
- oxidation is loss of electron
- reduction is gain of electron
most favorable conditions for minneralization and nitrification
-70% RH, 27 C, aerobic conditions
TN
- total nitrogen
- TON+DIN
LID
-low impact development structures