4.1 Introduction to water systems Flashcards
what kind of radiation drives the hydrological cycle
solar radiation
storages of the hydrological cycle
- atmosphere
- organisms
- soil
- oceans
- groundwater
- lakes
- rivers
- glaciers
- ice caps
transformation flows within the hydrological cycle
( a change in the state of water during the movement process)
- Evaporation: Water turns into vapour due to solar radiation
- Transpiration: Water vapor escapes from living plants (mainly leaves) and enters atmosphere)
- EVT (evotranspiration): total water loss from evaporation and transpiration
- Condensation: Water vapor cools into liquid droplets.
- Sublimation: Ice converting directly to water vapor.
transfer flows within the hydrological cycle
( the movement of water from one storage to another without changing its state)
- Surface runoff: Waters over land’s surface.
- Infiltration: Water seeps into/ is absorbed by soil
- Stream flow/currents: Movement of water in channels (ie. streams and rivers)
- Advection: the horizontal movement of energy or matter
- Percolatoin: the process where water moves downward through soil and rocks into groundwater)
human impacts on the hydrological cycle A
Agriculture
- Irrigation: the addition of water to areas where it is insufficient for adequate crop growth (can be taken from surface stores ie. lakes, dams, resovoirs)
-> increases EVT (added water = more loss to the atmosphere)
-> reduces Earths albedo (reflective sandy surfaces are replaced with dark green crops)
-> can cause salinsation (more water= more evaporation = more salt ‘left behind’ + promotion of salt-tolerant organisms = can shift ecosystem balance)
- Grazing
-> decline in inflitration due to compation of soil - Ploughing
-> increase in infiltration due to loosening of soil
human impacts on the hydrological cycle D
Deforestation
increased light intensity, temperature, wind speed, moisture at ground level:
-> organic matter decomposed at a faster rate
-> raindrop impact increases = compacts soil
-> EVT rates decrease (less plants (lower soil quality), less water on canopies)
-> overland runoff increases
-> increased soil erosion (less topsoil, less infiltration, lower soil fertility)
human impacts on the hydrological cycle U
Urbanisation
- removal of trees/vegetation: lower EVT/interception
- initial construction of houses, streets
-> decreased infiltration
-> increased stream sedimentation (build-up of soil, sand, other particles in rivers and streams)
- road construction/dams = can change water flows (speed, direction)
- large mechanical vehicles = compact soil -> less infiltration, less percolation, more erosion
Ocean circulation systems
driven by differences in temperature and salinity that affect water density. the resulting difference in water density creates a global “conveyor belt” of ocean currents that distributes heat around the world, so affecting the climate.
The Ocean Conveyor Belt
- Surface currents carry warm water from the equator towards the poles.
- As water cools near the poles, it becomes denser and sinks.
- Deep ocean currents carry cold water back towards the equator.
- This cycle helps distribute heat globally, influencing climate patterns.
link between the hydrological cycle and climate
- Water vapor is a greenhouse gas, meaning it traps heat in the Earth’s atmosphere. As temperatures rise due to other greenhouse gases (like CO₂), more water evaporates, increasing the amount of water vapor in the atmosphere.
This amplifies the greenhouse effect, causing further warming. This is a positive feedback loop. - Cloud formation increases global albedo and therefore lowers temperature. BUT cirrus clouds (low, thin) trap heat (infrared radiation) and lead to higher temps, contributing to gh effect.
- Ocean currents distribute heat, shaping regional climates.
Salinity notes (ocean circulation)
- hgher in warm seas (because of more evaporation)
- tropical seas: drops sharply with depth
- thawing of large icebergs = decreases in salinity (they lack salt)
Temperature notes (ocean circulation)
- varies at surface / little variation at depth
- large decrease with depth (thermocline) -> limits mixing of surface and deep water
Density notes (ocean circulation)
- higher temps = less dense
- lower temps = more dense
- lower temps + more saline + deep = very dense
- higher temps + less saline + surface = less dense
- dense water slips UNDER less dense water
Specific heat capacity
- amount of energy it takes to raise temps of a body
- more energy needed to heat water than land BUT water takes longer to cool
- places close to the sea: cool in day, mild at night
