River Environments Flashcards
What is the water cycle?
Water circulates between the sea, land and air in a closed system. The total amount of water in our planet never changes.
Where can water be stored? (On land)
Interception
Surface storage
Soil moisture
Groundwater
What is interception?
Water is stored on the leaves of trees and other plants.
What is surface storage?
Puddles.
What is soil moisture?
Water stored in the soil itself.
What is groundwater?
Water stored underground.
List the processes of the water cycle.
Evaporation
Transpiration
Condensation
Precipitation
Surface runoff
Infiltration
Percolation
Throughflow.
What is a tributary?
A tributary is a smaller stream that flows into the main river.
What is a confluence?
The POINT where two rivers meet.
What is a drainage basin?
An area of land drained by a river.
It is an open system, as the amount of water inside can vary.
List the parts of a drainage basin?
Source
Tributary
Confluence
Watershed
Mouth
What is a source?
The start of a river?
What is a watershed?
The border of the drainage basin.
If water falls on one side it enters the basin, if it falls in the other, it enters a different basin.
What is a mouth?
The end of a river.
What are the inputs of the drainage basin?
Precipitation.
What are the outputs of a drainage basin?
Evaporation
Transpiration
River carrying water to a lake or sea
What are the stores of a drainage basin?
Interception
Surface storage
Soil moisture
Groundwater
What are the transfers of a drainage basin?
Infiltration
Percolation
Surface runoff
Throughflow
Groundwater flow.
What are the channel characteristics of the:
Upper course?
Middle course?
Lower course?
Narrow, shallow.
Widens, deepens.
Deepest and widest.
What are the types of erosion in the:
Upper course?
Middle course?
Lower course?
Vertical
Hydraulic action
Abrasion
Attrition
Lateral
less hydraulic action
Some lateral
Deposition is more common.
What are the types of transport in the:
Upper course?
Middle course?
Lower course?
Saltation
Some traction at high flow
Suspension
Deposition
(All methods seen)
Suspension
What is the size of load in the:
Upper course?
Middle course?
Lower course?
Large, angular
Smaller and rounded
Sand, silt and clay (small)
What is the cross sections of the:
Upper course?
Middle course?
Lower course?
Look at your notes I can’t put photos on here-
What are the two main directions of erosion in a river and how do they take place?
Vertical erosion. Material scrapes at the riverbed, deepening it and creating steep valley sides.
Lateral erosion. If the river flows quickly enough, it has enough energy to wash away the sides of the river.
What are the 4 types of erosion?
CASH
Corrasion/ Abrasion:
Sandpaper, like rocks grinding against each other.
Attrition
Rocks smash together and break apart.
Solution
Acidic rainwater reacts with soluble materials
Hydraulic action
The water itself forces rocks apart or wears them down.
What are the 4 types of transportation?
TSSS
Traction:
Large stones are rolled along the riverbed.
Saltation:
Pebbles are picked up and bounced along the riverbed.
Suspension:
Sand or silt is picked up by the river and carried along.
Solution:
Minerals dissolve into the water of the river, and flow with it.
When is deposition more likely to occur?
River enters a lake or sea, slowing its flow.
There is an area of shallow water, slowing its flow.
The load is increased suddenly, Eg, after a landslide
The river is on to its floodplain, where it flows very slowly.
How do you calculate discharge?
Volume x velocity.
Measured as cubic metres/sec or cumecs.
How do waterfalls form?
(Also give an example of a waterfall)
E.g high force- river teese
There is a layer of hard rock over a layer of softer rock.
The softer rock is more easily eroded so the hard rock is undercut.
A step is formed by the process of abrasion and hydraulic action.
The river falls into a plunge pool and eventually the overhanging hard rock will collapse due to this undercutting.
The waterfall retreats upstream, forming a gorge.
What is the correct diagram to use when describing a waterfall?
Check your notes, I STILL can’t put photos on here.
What is a meander? What is its characteristics?
Meanders form in the middle/lower course of a river.
They are bends in the river that form as the gradient evens out. Where water flows fastest in the channel it spirals downwards, causing vertical erosion, deepening the river and forming a river cliff. On the opposite side the water flows much slower, forcing it to deposit its material and form a slip off slope.
Describe the cross section of a meander
Like the Nike logo.
Check your notes.
What are levees?
Levees are a buildup of sediment on the rivers embankments. They can be either natural or man made, and can help protect the river from future floods.
How do levees form?
When a river bursts its banks (floods) it will slow rapidly as it enters the shallow, high surface area floodplain. This causes it to drop its load, with the heaviest material deposited first. Overtime, after multiple floods, there will be a noticeable buildup of material on the riverbanks, called levees.
Learn the diagram of a flooding river and levee formation
Ok.
What is a floodplain?
A floodplain is a flat area of land surrounding a river, which will naturally fill with water during a flood. These areas often have fertile soil, which is desirable to farmers.
Learn the diagram of a floodplain at normal water levels and during a flood.
Ok.
