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A-Level Geography 16/05/14 Unit 2 Mark Scheme
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In total I think I got (31/50), which is bad considering AQA will mark harshly and I would say decreasing the mark you give yourself by 10% gives a much more accurate mark.
Rivers-I think I got (18/25)
The diagram showed that no completely flooded rivers occured within 60km of a settlement, main completely flooded rivers about 800km from Arabian sea,areas in south west and north east that weren't flooded due to not being near any rivers.(I think I missed the main point that flooding severity decreased as you got further and further away from the rivers).(4)-I think I got 2.
One advantage is that the diagram shows a clear visual representation of the flooding severity but One Disadvantage is that areas close to being completely flooded would look like they flooded a lot less than areas that were just about completely flooded and this was due to having a key of only three colours and this could lead to less aid and international support in the area.(4)-I think I got 2.
Physical Factors that cause flooding are due to the natural characteristics of the area and Human Factors are due to the impact/influence that humans have made to the area.Physical Factors include steep slopes causing water to flow faster not giving the soil much chance for infiltration to occur increasing peak discharge decreasing lag time causing flooding.Large amounts of rainfall in a short period of time cause Hortonian Overland Flow as the soil can't keep up with the large amount of rainfall reducing infiltration leading to more surface runoff causing lower lag time more peak discharge causing flooding.Human Factors are the building of dams in very bad rainfall conditions which force them to discharge lots of water through the sluice gates and the huge sudden release causes river levels to rise rapidly as shown in the Vietnam,2013 flood where the Ba Ham Dam in Phu Yen was dischargin 1,400 cubic metres per second.Another Human Factor is deforestation which reduces interception which slowed down precipitation because it had to be transferred by throughfall or stem flow before it reached the ground and by this time it may have evapotranspirated, trees also take up water from their roots(abstraction) reducing the supply of throughflow to the river and their roots strengthen the soil preventing it from being washed into the river reducing channel capacity causing flooding.Physical Factors are necessary to cause flooding but Human Factors can increase the severity of the flood.(6)-I think I got 5.
Plot the two points carefully using the scale it was 4 per small square and 20 per large square 333 was one of the points what was the other one(1)-I think I got 1.
Range= highest value-lowest=414-220=194mm(1)-I think I got 1.
Interquartile Range is calculated through finding the lower quartile which is the (n+1)/4th number in the rank order and the Upper Quartile which is the 3(n+1)/4th number in the rank order you can count to work out what number is that rank(I definetley referred to counting but I'm not sure exactly how I worded this) and if you have a rank of 7.5 then you average ranks 7 and 8(probably not required).You then subtract the upper quartile from the lower quartile to get the upper quartile.(4)-I think I got 3.
The Pakistan Floods have caused lots of vegetation to be flooded, houses to be lost as shown in Figure 3.Pakistan is an LEDC so is agriculture based so people will struggle to afford to feed their families etc, water will be contaminated and could cause illnesses like cholera and Hepatitis A(water became infected with this in the Carlisle Flood,2005) and houses lost will leave people without shelter.The vegetation losses could have worldwide impacts as shown in the Vietnam floods, 2013 which is also an LEDC because 17% of the soya crops were lost rising prices worldwide, which could lead to losses in businesses as people will not pay higher prices.Lots of money will be given by international aid putting pressure on countries struggling from the recession.(5)-I think I got 4.
I don't think I did too well in Section B so mark with caution and please comment so that I can put the answers right.
Fieldwork Investigation-I think I got 13/25.
Aim-To investigate downstream changes in river characteristics in accordance with the Bradshaw Model in the Glenderaterra Beck,Threlkeld,Lake District,Cumbria.UK, the focus was on velocity.There were two hypotheses the null hypothesis that they would be no change in river characteristics downstream and Alternate Hypothesis that there would be a change in river characteristics downstream(0)
I measured how velocity changed downstream by measuring the width with a tape stretched from one bank to the other and divided the width by 4 and measured at every quarter of the width using a flowmeter half way up from the depth away from the bed and the banks due to increased friction reducing velocity, recording readings facing downstream to prevent reducing the flow of water.(Link to Aim which I missed is that velocity is a river characteristic that changes downstream and is said to increase in he Bradshaw model due to reductions in friction due to erosion of the bed and banks making them smoother reducing hydraulic radius etc. if it increased then Alternate Hypothesis would be accepted and Bradshaw's Model accepted if it decreased the Alternate hypothesis would still be correct but Bradhaw's Model would be rejected and if there was no change the Null Hypothesis would be accepted and Bradshaw's Model rejected.(5)-I think I got 2.
One technique of data presentation was a Line Graph(0).Drawing of line graph under x axis connected up to represent bed of river, width labelled on the x axis and depth on the y axis-with the area bounded to the curve shaded and labelled cross sectional area.(4)-I think I got 3.
The technique was justified because the line graph gave a clear visual representation of cross sectional area and the line graphs could be stuck on a map to make a Locational Bar Graph to show water river characteristics caused the increases in depth, width and cross sectional area eg.increased lateral and vertical erosion due to input of sediment between tributaries causes lots of vertical erosion by abrasion as they are transported by traction and volume of water would mean more water not in contact with bed and banks causing more lateral erosion, increases in depth and width increase cross sectional area.(5)-I think I got 3.
My conclusions showed that velocity increased downstream with a spearman's rank coefficient of 0.497 for n=18 values which is above the critical value of 0.05 which is 0.475 making the results statistically significant.I have learned that it was caused by the large amounts of erosion by the river laterally and vertically caused by the large input of sediment from tributaries,scree slopes and mines transporting sediment by traction causing vertical erosion, as the sediment eroded the bed and banks it became smoother reducing friction increasing velocity.Sediment Roundness/Size didn't show any correlation from the Scatter Diagram and this was due to the large input of sediment from scree slopes, mines and tributaries.(You could say that you learned better methods to measure rivers like using a chain that falls to the bottom that can bend around an uneven bed rather than width+2*depth, which I put in my booklet I didn't put this though.) (6)-I think I got 2.
Improvements to my investigation would be to stratify where I took my velocity readings because you couldn't always get the flowmeter into the water because it was too shallow or a large rock blocked the flow of water.I should also have picked more sediment at every section of the width to reduce bias as people picked out rocks that they could get a hold off which lead to no correlation between sediment size and distance downstream.Systematic Sampling divisions should have increased further downstream as the width increased because this lead to huge gaps on river sections which had large widths making the Line Graph's Cross Sectional Area very inaccurate because the missing sections could have been very shallow or deep.I should have used poles to measure gradient because it was very hard to look at the same point on someone but a dot on the pole would be easier and this would make it possible to see whether the decreases from 15 degrees to 3 degrees were correct.(5)-I think I got 3.
I would say 100 UMS-37 A-29 B-25 C-21 D-18 E-15 because there were lots of theory questions that you would expect in GEOG1 and they usually have lower grade boundaries than skills and they normally always give you the formula for calculations but the asked you to describe how you would calculate interquartile range without a formula(I was OK but I doubt most people would be thats why there are formula booklets in Physics etc.) even though in another paper they gave you formula for interquartile range, the figure for Question 1 was quite unclear and to a much less extent the figure on the last question to Section A which just seemed to show flooded vegetation and the skills questions were very vague "what did you learn" and were uncharacteristic of previous papers wit questions like that and sketching your data presentation format and I would imagine there would be some people who were only taught what to write and stuff so that question would have been difficult and the improvements question was unusual and vague too, this would have meant a lot of people who used model answers would have struggled and there weren't any too easy questions like explain your aim and geographical theory and they even asked you to state your aim for 0 marks(it has happened before but not always).
a much harder paper than last year in both sections,I would have to say particularly Section A because the strange unseen questions in Section B weren't that much harder than last year but requiring more than model answers-Section A last year was a big joke with a very easy population distribution figure, easy spearmans rank anomaly and critical values, the graphing technique I struggled with and got marked down for extending my scale beyond the data and unclear points and the 5 marker required limited knowledge and was very simple on negatives and positives of increasing and decreasing population no real explanation needed just references to effects with the figures there to help you compared to the large 6 and 5 markers in Rivers without much help there for you.