Hydrology Flashcards
Why do people use hydrology?
To use resources more sustainably. The cycle is linked to many other processes. It is fast compared to most other cycles.
What are the four elements of the watershed scale?
Where does water go? How long does it stay there? What is its flow path? What does it pick up along the way?
What percentage of water is fresh?
2.6%
What are some key properties of water?
High heat capacity. Absorb infrared and ultraviolet light
What is a sensible heat transfer?
Measurable. Temperature measurement
What is latent heat transfer?
The energy needed to heat molecules
Which front produces ppt faster?
Cold front
What is the spatial interpolation?
The space in between measuring devices
What are the two factors affecting evapotranspiration?
Energy required to supply latent heat
Capacity to transport
What is Potential evapotranspiration?
The ability of the atmosphere to move water
What is the actual evapotranspiration?
Quantity of water actually being moved
What is the water budget equation?
Flow = rain - evaporation +/- water storage change
What two elements are important in the sub service?
Gravity and pressure
What type of material is more porous?
Material with small grain sizes
What are two elements which determine a materials percolation rate?
Connectivity and Porosity
What are Darcys three laws?
- Water flow depends on the length and width of a river bed
- If you raise the energy of water then the water flow increases
- Materials determine water flow
What is quick flow and base flow?
Quick flow: water run-off that quickly enters the water
Base flow: water that enters slowly, it maintains the stream flow over time from the groundwater into the stream
What are the two reasons for overland flow?
Infiltration is exceeded: Hontonian overland flow
Saturation is exceeded: Saturated overland flow
What is through flow?
Water that has infiltrated the surface
What factors determine how fast a river flows?
Gravity, turbulence, pressure gradient
What is hydrostatic pressure?
Force at a point related to the weight of the water and the atmosphere directly above it
What form are substances in the aqueous phase?
Solutes - liquids
What factors affect how a particle forms?
Temp, PH, Ion charge, Composition
What is tracer contaminant?
Very soluble movement in the water
What is highly sorbed and what process does it create?
Particles that stick to soils. Retardation
What is advection?
Movement of chemical mass with flowing water
What is diffusion?
Particles which try to come to equilibrium. High conc to low conc
What is hypodynamic equilibrium?
The smoothing effect caused by velocity variations
What happens when groundwater evolves over time?
TDS changes, Ratio of major ions changes, Oxygen is depleted, Reduction occurs - Timing is variable
What is the water quality?
Balance of nutrients
What is eutrophication?
A process where lakes ago and become more productive - more algae blooms
What is Anthropogenic eutrophication?
Water pollution caused by excessive plant nutrients entering a lake
What are nutrients of concern in our waterways?
Nitrate, Phosphorous, Carbon
What are some contaminants of NZ waterways?
Pesticides, Heavy metals, organsims
What is point source pollution?
Direct pollution into rivers
What percentage of NZ waterways are impacted by humans?
42%
