Showing posts with label rivers. Show all posts
Showing posts with label rivers. Show all posts

Friday, 16 January 2015

Which Case Study? Rivers and Population Resource

So, a common error in the exam, particularly with essay questions, seems to be accidentally using the wrong case study and ending up not really answering the question properly. Understandable, since the pressure of being in an exam could make you panic and write about the first case study you can remember.

You don't want to end up like I did in my first year at university and go into the exam hoping the question on 'sea ice' would come up. After frantically scanning the question options for the words 'sea' and 'ice' and not seeing them anywhere, I resigned myself to answering a question on climate change using nothing but what I could remember from 'An Inconvenient Truth'. I still passed, but only just, which did not do justice to my weeks of hard work and revision.

The point is, upon leaving the exam I bumped into a friend who expressed her great relief that the sea ice question had come up. 'What?!' I exclaimed with a look of horror, 'are you talking about?!'.


Monday, 8 December 2014

The Storm Hydrograph Revision and Exam Technique



So, I spent about 40 hours (seriously, it took me HOURS) making a video tutorial to help my AS class after they almost all failed some homework questions on the storm hydrograph. I didn't have the lesson time to go over it again so I thought by making a video they could learn about it in their own time. Here are the questions if you'd like to use them:


Lets hope their homework has improved when they resubmit it! And I'm also hoping there's some more students out there who can benefit from my video. Please subscribe to my channel - if I get enough viewers I'll make some more videos and take requests. Even thought it took me a long time I actually enjoyed doing it, and it's worth it if it helps out some fellow geographers! Hope you like it!

p.s. apologies for the few mistakes and blurry images, it's my first try so it's not perfect, and to be honest I think I will jump out the window if I have to spend any more time editing it! However, it you spot anything that is totally wrong or incoherent please let me know! 

I now have a new appreciation for all those other video tutorials on YouTube....!!



Friday, 28 March 2014

PAKISTAN FLOODS 2010

FLOODING IN A LESS DEVELOPED COUNTRY


BACKGROUND INFO

·         GNP per capita ~$2700

·         Flooding began in July 2010; at one point ~1/5 of Pakistan’s total land area was submerged including 69,000km2 of fertile crop land.  


CAUSES

·         The river Indus normally floods every year but in 2010 there was prolonged and heavy e.g. 274mm fell in 24 hours in Peshawar on July 29th 2010. More than half the normal monsoon rains fell in only a week instead of 3months. One reason could have been unusual conditions in the polar jet stream.

·         The river Indus carries a lot of sediment and mud from the Himalayas, which silts up the channel and make it more prone to flooding.

·         Others think anthropogenic climate change could have strengthened monsoon rains, whilst deforestation in the Himalayas has reduced the river’s lag time.

·         Levees built for flood defence were breached and caused sudden huge releases of floodwater.

·         The massive human impact occurred because 2/3rds of Pakistan’s citizens rely on agriculture for their income and many of them live close to rivers for access to water and fertile alluvial soils.

·         In some places such as the Swat Valley, infrastructure had already been weakened by the 2005 earthquake and not yet repaired.


IMPACTS

·         Flooding submerged whole villages within the Islamic Republic of Pakistan, killing at least 1,600 people, according to the UN. Twelve million were affected in Khyber Pakhtunkhwa and Punjab provinces, while a further two million were affected in Sindh.

·         Floods directly affected about 20 million people (more than the boxing-day tsunami and Haiti earthquake combined), mostly by destruction of property, livelihood and infrastructure including 100s of bridges and 200 health facilities.

·         The World Health Organization reported that ten million people were forced to drink unsafe water.

·         The total economic impact may have been as much as US$43 billion including damage to the important cotton industry (Pakistan was previously the 4th largest cotton producer) as 80% of fields were left waterlogged in some areas and crops and livestock were drowned.

·         Illnesses such as gastroenteritis, diarrhoea, and skin diseases occurred due to lack of clean drinking water and sanitation. Pakistan also faced a malaria and cholera outbreak.

·         There were also long-term impacts including: food insufficiencies leading to malnutrition, damage to schools, Taliban insurgencies and an increase from 33-40% of people living below the poverty line.


RESPOSES

·         France donated €1.05 million and 35 tonnes of emergency supplies including tarpaulins, blankets, shelters and anti-cholera medicines, while the UK donated £134.5 million.

·         The United States donated 71 million dollars as well as 56,000 ready meals and two temporary bridges to help reconnect. They also built water filtration plants.

·         However after 6 months charities were surprised by the slow international response as only 56% of the $1.96 billion requested by the Pakistani government had been given. This could be due to the global phenomenon of “donor fatigue”. President Zardari was also criticized for his slow response. Many felt the Pakistani Army was slow to rebuild bridges, deliver aid or set up relief camps.

·       In the longer term flood warning systems are being funded by charities such as Oxfam and the US government, including radio stations used to educate people of the danger of flood water and the different toxins and diseases in it meaning that people will be more prepared next time.


Discussion point: Who was worst affected by these floods? Could they have been avoided?


Friday, 12 April 2013

The Formation of a Meander

Sometimes I find poems helpful for remembering things! So here's one I wrote about meanders, which includes lots of key geographical words you should be using to describe them!

Rivers always take the path of least resistance
Winding round obstacles into the distance
Even in straight channels bars of sediment seem to form
Alternating deep and shallow sections is the norm’
At alternating intervals of 5-7 times the bend*
The bars deposited when low flow conditions tend
Riffles and pools are they names these features go by
Weaving in between then, the thalweg must comply.

Riffles will reduce the river’s efficiency
Slowed by friction the water has no energy
To carry its load, so it drops it right there
Forming what’s known as a slip-off slope or point bar
While the inner bend is built up by deposition
On the outer bend the river’s flowing fast with a mission
The high hydraulic radius in pools is the reason for
Undercutting by abrasion and hydraulic action more.

This process is perpetuated by helicoidal flow
A corkscrew like movement about which you need to know!
This erodes the river cliff of one meander’s outer bend
Depositing downstream in the next one’s inner bend
As these processes continue the meander slowly migrates
Moving both laterally and downstream at a steady rate.



* 5-7 times the width of the channel – I wrote ‘bend’ because width’ didn’t rhyme!

Monday, 6 February 2012

Kissimmee River Restoration

For everyone who thought the River Quaggy was a somewhat... uninspiring case study of soft engineering, how about the River Kissimmee in Florida? This is soft engineering on a large scale! Check out this website for more info! (if anyone wants to write up some case study notes to post on here they would be most welcome!).


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