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Description
Flashcards by Ronnie Harris, updated more than 1 year ago
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Created by Ronnie Harris
almost 3 years ago
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| Question | Answer |
| What is a drainage basin | A drainage basin is an area of land drained by a river and its tributaries |
| Whats is the source of a river | The beginning of a river |
| What Is the mouth of the river | Where the river meets the sea |
| What is a tributary | A tributary is a small stream that then joins a larger river |
| What is the watershed | A boundary of a river basin usually high land |
| What is a confluence | The point where two rivers meet |
| What are the 3 types of weathering | Mechanical,biological,chemical |
| What are the 4 types of erosion | Hydraulic action,abrasion,corrosion,attrition |
| What are the 4 types of transportation | Suspension,traction,solution,saltatio |
| What are the 2 types of mass movement | Slumping and sliding or rotational slipping |
| What happens to channel width downstream | Increase |
| What happens to velocity downstream | Increase |
| What happens to discharge downstream | Increase |
| What happens to gradient downstream | Increase |
| What river have we looked at to see the river changes downstream | The river dee |
| Give examples of an impact the uks weather climate has had on river processes | One example of an impact the uks climate has had on river processes could be that erosion rate will be greater with greater discharge as the river flows faster and so has more energy to erode.Therefore,rivers in wetter climates will erode more material than those in dryer climates, widening and deepening river valleysand increasing the amount of eroded sediment. |
| Give examples of an impact the uks weather and climate has had on landscapes and landforms | During times of heavy rainfall, trees on the river banks can have there roots undermined by erosion and mass movement, eventually causing the bank to callapse |
| Give 2 river landforms found in the upper course | One landform is a very shaped valley Another landform is and interlocking spur |
| Explain their formation and reference to geology erosion processes | . Rivers do not have a lot of energy near the source due to have such small discharge. They erode vertically(by hydraulic action and abrasion) resulting in v shaped valleys. However they do not have the power to laterally erode the hard Rock of the valley sides (the spurs) As a result they flow around the spurs,resulting in the spurs from each side of the valley interlocking. |
| Give 3 river landforms found in the middle or lower course | One landform is a waterfall in addition another 1 is a gorge and then the third is a meander |
| Explain their formation and reference to depositional and erosion processes | Meanders are formed by some erosion processes such as hydraulic action and abrasion.in the middle stages a river has more discharge and so has more energy to erode laterally,forming large bends.The fastest flows occurs on the outsides of the bends where it is deeper and so there is less friction.the fast flow results in greater erosion by hydraulic action and abrasion.this leaves a steep slope called a river cliff.the slower flow is found on the inside bends cause by deposition this results in more frictions so the river has less discharge which is why deposition takes place, this creates a point bar also know as a slip off slope.An underwater current take some or the eroded material from the river cliff across the riverand deposits it on the point bar.these bends can migrate over time |
| Give 2 river landforms found in the lower course | Levees floodplains |
| Explain their formation and reference to depositional and or erosion processes | Levees are natural banks found either side of the river on a floodplain(humans can artificially raise them).they are formed when a river deposits material like alluvial or silt.the largest material is dropped first as it is heaviest because the river doesn't have the energy to carry it.this is called sequential deposition.the smaller material is carried further during floods as it is lighter.this results in the land flattening creating a floodplain.the banks grow larger over time. |
| Give an example of how urbanisation can affect rivers such as the river dee. | The building of roars and drains means that water can reach the river more quickly after rainfall.this means that the river is much more likely to flood because of the disruption in the balance of water flow to the river. |
| Give an example of how agriculture has affected the river dee. | Near bangor-on-dee in the middle course of the river,earth embankments are used to protect farmland and properties from flooding a land drainage pumping system at Worthen urban meadows helps remove excess flood waters |
| Get how industry has effected rivers such as the river dee | A further reason for channelisation was to improve navigation of ships,which is beneficial for the industry. |
| What is the difference between physical and human causes of flooding | Physical causes of flooding is the natural cause of flooding where as human is caused by man made influences. |
| Explain how heavy rainfall increases the risk of flooding | If there has been heavy rainfall for a number of days then the ground becomes saturated.this then increases the surface run off so more water straight into rivers causing them to flood. |
| Explain how impermeable rock can increase risk of flooding | Rainwater cannot soke through impermeable rock so it will flow straight to the river as surface run-off, so the river will receive more water at one time,increasing the risk of flooding. |
| Explain how increased temperature after snowfall can increase risk of flooding | This will cause the snow to melt resulting in rapid increase in the amount of water entering the river,increasing the flood risk. |
| Explain how a long dry period of weather can increase the risk of flooding. | This will cause the siol to become very hard so the water cannot soke through it.as a result rainwater will run straight to the river as surface run off,increasing the amount of water entering the river at one time, and so increasing flood risk.. |
| Explain how river beds becoming silted up can increase risk of flooding. | This makes the channel smaller and so theres less room for water,which increases the risk of flooding |
| Explain how steep valley sides can increase risk of flooding | Rainwater quickly runs down the steep slopes,resulting in more water entering the river at one time,so increasing the chance of flooding. |
| Explain how deforestation can increase risk of flooding. | There is less interception of rainwater by leaves,and less water is soked up by roots.therefore,the water reaches the river more quickly increasing the chance of flooding. |
| Explain how building on a floodplain increases risk of flooding. | Water is unable to soke through tarmac and so it runs straight to the river as surface run-off. Also,water that goes down the drains runs very quickly to the river.this means the river receives more water at on time,increasing the risk of flooding. |
| Explain how farmers plowing up and down slopes instead of around the hillside. | The channels created by plough all rainwater to travel faster to the river,so the river receives more water at one time,increasing risk of flooding. |
| Explain how bursting a dam can increase flood risk | Excess water will enter the river channel,causing the flooding of a large area. |
| Give three main reason why there is a increasing flood risk in the UK. | Increasing population changes in land us Changes land use e.g.more urban surfaces impermeable Changes to whether patterns,particularly linked to climate change.for example,in December 2013 and January 2014,the UK experienced the wettest two month period of rainfall since 1910.the river Thames recorded its highest discharge for over 60 years |
| What is a storm hydrograph | Q hydrographic shows how a river responds to a storm event |
| On a storm hydrograph what does a rising limb represent | A rising limb represents the rapid rise in water after a period of rain |
| What is the lag time | The lag time,Wich is the difference between the time of heaviest rainfall and the point in which the river contains the largest amount of water. |
| What does the falling limb represent | The reduction in the amount of rainfall reaching the channel |
| Give an example of how floods can affect people and the environment | Hoemes can be destroyed resulting in large insurance claims and money having to be spent on temporary accommodation. Damage to properties and their sewage pipes can contaminate rivers and the sea ,wich canbe harmful to wildlife |
| Give some located examples of major floods in the UK and their specific effects | North Wales,Cumbria and South West england-2012. Rained persistently from April to November. The ground became saturated, causing huge amounts of surface run-off and flooding. 9 million people died 8000 homes were destroyed £600 million of crops were ruined(economic) |
| What is the difference between hard and soft engineering | Hard engineering is good at reducing chances of flood where as soft engineering is good atreducing impacts of flood.soft engineering is not good at preventing floods compared to hard engineering with is very expensive because of lots of construction work. |
| Give examples of hard engineering and techiniques | Enbankments-these are raised banks along the sides of a river.to increase discharge the river can hold. |
| Give examples of soft engineering techniques | River restoration-restoring a rivers natural course |
| Give examples of how land use can be managed to reduce risk of flooding |
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