Test One Second Year: Rivers Flashcards
Name 3 stages of a river
Youth stage,mature stage and old stage
Define the word erosion
It is the wearing away of material from the surface.
Explain the term transportation
It is the removing of material that has been eroded
What is deposition
It is the dropping of material that has been transported
What is hydraulic action
It’s the physical force of moving water that wears away and breaks of the rock and soil from the banks and bed of the river
What is abrasion
It’s when the materials carried by the river wear away the bank of the river
Define the term attrition
It is when small stones in a river are broken up as they hit of each other
Explain the term solution
Rock such as limestone and soil that are dissolved by acid in the water
What is solution
It’s when other materials dissolve in the water and are carried away by the river
What is river deposition
It’s when rivers deport or drop there load
What is a V-Shaped valley
A V-Shaped valley is a steep-sided valley in the shape of a V. It is shaped by vertical erosion
What are interlocking spurs
Interlocking spurs are areas of high ground that jut out at both sides of the V-shaped valley
Describe a waterfall
A waterfall is a vertical drop in the causes of a river found in the youthful stage
Give me an example of a waterfall
Tore. Co Kerry
What are the processes of a waterfall
Erosion: hydraulic action,abrasion,attrition and solution
How does a waterfall form
It is formed where a band of hard rock on top of a band of softer rock. Over thousands of years the softer rock is eroded quicker than the hard rock by the process of hydraulic action and abrasion. Overtime the slope becomes steeper and a waterfall is formed. As water drops over the waterfall it carries its land with it . This helps the waterfall to erode a deep hole called a plunge pool. The falling water cuts under the waterfall to form an over hang of hard rock which eventually collapses. This process repeats itself so that the waterfall retreats upstream to form a garge
What’s an example of a meander
The river Shannon
What process are involved in meanders
Erosion(hydraulic action) and Deposition
What is an oxbow lake and give me an example of one
An oxbow lake is a horseshoe-shaped lake that form when a meander is cut off from the river
Eg. The rivers Liffey and Moy
What is a levees
A levees is a build up of alluvium on the banks of a river. Levees are caused by floods
What are two examples of a levees
The river Moy and Liffey
What are the processes of levees
Deposition
How are levees formed
The river carries a large load of sediment know as alluvium. During floods the river spreads out on both sides and deposits the land it’s carrying. The heaviest material is dropped of first. Over time a thick layer of alluvium builds up on flat land by the river. This is the flood plain. The alluvium makes the soil very fertile and generally good for farming. The highest point reached by the river when in the flood is called a bluff line
Name 2 land forms you find in the lower stage
Waterfalls and v-shaped valleys
Name 2 land forms you find in the middle stage
Meanders and Oxbow lakes
Name 2 land forms you find in the old stage
Flood plains and Levees
