Fresh Water syllabus Flashcards
State all the outputs of the hydrological cycle?
Evaporation, Transportation, River runoff
What are the inputs of the hydrological cycle?
Precipitation
Tell me all the transfers of the hydrological cycle
Stem flow/through fall, infiltration, percolation, through-flow, surface runoff, groundwater flow
What are transfers
The transfer of water between stores
All the stores of the hydrological cycle
interception, surface storage, soil water, groundwater, channel storage
What are drainage basins divided by
watersheds
What is a closed drainage basin?
Rather than flowing into an ocean, the water flows into an inland depression such as a lake. Surface water is not lost via river etc, it’s lost via percolation(into groundwater)
Describe what exactly inputs are
the conversion and transfer of moisture in the atmosphere to the land
What a=characteristics of precipitation which affect hydrology?
Amount
Intensity
Type
Distribution
What is evaporation
Solid to liquid or liquid to gas
What is evapotranspiration
The process of water escaping plants and entering the atmosphere
What is potential evapotranspiration
The potential amount of water loss if vegetation would have an endless supply of water
What is transpiration
the exhalation of water through the plants stomata
What affects transpiration?
Temperature, humidity, water available, colour of surface
What is infiltration ?
Water soaking into the soil
What affects infiltration?
Soil capacity, vegetation
What is overland flow and when does it occur?
When precipitation exceeds soil capacity, when soil isn’t very permeable
What is through-flow and through which streams does it flow?
It flows through the soil through percolates and natural pipes
What is wilting point
The amount of water which results in the permanent wilting of plants
What are aquifers
Simply rocks that contain a significant amount of water
How does water enter aquifers ?
The rocks in the top are permeable. Percolation occurs
What acts as a natural regulator to the hydrological cycle?
Aquifers because the water moves out and within very slowly. They save water for long dry periods.
What is the cryosphere?
The snow and ice environment. Stores over half of the earths water and usually occurs in high altitudes
What is river discharge
The amount of water passing a given point of a river over a set time. CSAx mean velocity
What a re conditions necessary for a turbulent flow?
Meanders, high velocities, gravitation
What is laminar flow
Where sediment remains
What conditions are needed for a laminar flow?
Shallow channels
Low velocities
Meandering
How does turbulence happen?
Through a fast velocity and channel bed roughness
Types of Erosion
Abrasion
Attrition
Solution
Hydraulic Action
AASH
How to remember the 4 types of erosion
AASH
What is abrasion
The wearing away of the bed bank by sediment. Sediment is carried via the channel. Heavy sediment
What is attrition?
The wearing off of river load. This creates smaller and rounder particles
What is solution?
The removal of chemical ions, especially calcium. Happens more often when load passes limestone
What is hydraulic action?
When force of air and water create pressure on the river bank. Air bubbles form and implode and crack the bank. Widens the river bank.
What makes you remember Transportation?
TSSS
Types of transportation
Traction
Saltation
Suspension
Solution
WHat is traction?
The rolling of pebbles along the river bed
What is saltation?
The frog-leap motion of small stones
What is suspension
The carrying of suspended, very fine, bedload via the river channel
What is another form of transportation which doesn’t include bed load?
Floatation- leaves
Why is it easier to transport sand than small stones?
Sand is lighter and requires more “entertainment”
What changes in monsoonal rivers during seasons?
They carry more sediment in the wet season due to higher velocities
What are monsoonal rivers?
Rivers that flow during the wet season but often dry out in dry weather
Explain the formation of a waterfall
When a stream flows over rock, the surface rock is softer than the underneath harder rock. Ober time, pieces start chipping away and a plunge pool is creates. Additional rock is chipped and falls as the rock is unsupported. The plunge pool deepens.
What erosion technique is used during the creation of waterfalls?
Hydraulic action
Explain the formation of v-shaped valleys
River cuts into the bedrock causing vertical erosion. Loosened material from the bank of the falls into the river, increasing the load and therefore erosion such as abrasion. Over time the river erodes laterally.
Explain flood plains
They are areas of low relief/gradient which are created to provide area to flood. They are surrounded by valley walls.
Explain the creation of meanders.
A river gains more velocity and is pushed outside of its bank due to not enough capacity. Here, an oxbow lake is created. When this area fills up it finds its way and rejoins the original stream, creating meanders.
How are levees formed ?
Through repeated floods of a river. The sediment is deposited in the outer parts of the bank and flood plain. This builds up over meany floods and runs parallel to the stream
How are deltas formed?
The river needs to carry a large amount of sediment. The river and mouth tend to be very vegetated. Deltas are formed by rapid drops of stream velocity. They bleed into lakes and seeds
How are deltas organized?
The finest material is moved out the furthest, bottom set bed
Middle set med- middle heavy sediment
Heaviest material is further towards the mouth
What is a drainage basin?
A set of land were various water sources flow into one.
What is an endoheic basin?
A basin which keeps its water, it does not flow into another EXCEPT for swamps and lakes. NO OCEANS
What is lag time?
The time between peak rainfall and discharge
What do we know when peak flow is low?
The landscape has high infiltration rates
What does the rising limb of a hydrograph represent?
The amount of time it takes for discharge to develop
What is irrigation ?
Applying controlled amounts of water, including minerals and salts, to agriculture in hopes to assist crops
What is salinization
increased salt in the soil
How does irrigation result in salinisation?
Water remains on the surface of the agriculture land. This means it evaporates very quickly. Salts and minerals do not have the chance to be diluted or evaporated and therefore build up. Salinity forces the water to move out of the plants into the soil. This dehydrates plants:
-stunted growth
-economic losses
-increased soil erosion
Example of overland fresh waters
Lakes
Glaciers
Reservoirs
Vegetation
