Worth 30% of AS. 1 hour 2 parts - Part 1 is skills tested via either rivers or population - Part 2 is asking about your fieldwork Worth 30% of A2. 1 hours 2 parts - Part 1 is asking about your fieldwork - Part 2 is about your application of skills We are suggesting you sit this exam a year early so you have an option to re- sit at A2. Unit 4A is a more challenging examination that the AS equivalent Unit 2. The questions have to demonstrate elements of both synopticity and stretch and challenge. Essentially, the differences between the two examinations can be summarised as: Unit 2 assesses what I did on my fieldwork Unit 4A assesses why I did what I did on my fieldwork 1.Theory underpinning enquiry 2.Hypothesis 3.Aim 4.Location 5.Risk assessment 6.Data collection HOW 7.Data collection STRENGTHS/ WEAKNESSES 8.Data presentation 9.Analysis 10.Conclusion 11.Evaluation Theory: Bradshaw's model. What is the difference between an aim and a hypothesis? Aim - is what your going to do Hypothesis - is what you think the outcome will be Aim: TO INVESTIGATE DOWNSTREAM CHANGE IN THE RIVER HARBOURBE, SPECIFICALLY THAT AFFECTING DISCHARGE, IN LIGHT OF BRADSHAWS MODEL FOR DOWNSTREAM CHANGE Hypothesis: As the distance increases downstream cross sectional area and velocity will increase. Null Hypothesis: There is no relationship between cross sectional area and velocity. Aim IMPORTANCE OF THEORY: - Prior knowledge needed a theory which we would understand from prior study in order that we could understand the processes involved, make an educated hypothesis to begin & make educated conclusions. Had already studied Bradshaw. - Location needed a theory which we could investigate in a safe, accessible, available location - Risk assessment something we could safely test. Bradshaw safe in upper course - Equipment a theory which would not need sophisticated/expensive instruments to test - Challenge & learning one which would challenge our skills & allow us to learn new ones & new processes. Bradshaw involved investigating several different variables TO INVESTIGATE DOWNSTREAM CHANGE IN THE RIVER HARBORBE, SPECIFICALLY THAT AFFECTING DISCHARGE, IN LIGHT OF BRADSHAWS MODEL FOR DOWNSTREAM CHANGE Potential questions: importance of theory in choice of aim/ reason for choice/ importance of location in choice/ relevance of a method/ evaluation of success in light of the aim. REASONS FOR CHOICE: (from mark scheme ) - Knowledge - Theory ability to test this. Link with location -Risk assessment -Suitability & availability of location -Available equipment, time & resources EVALUATION: - Success of sampling method accuracy; reliability; validity helped reach aim - Appropriateness of location for reaching aim - Conclusions reliability & validity. Statistical test results: null hypothesis accepted goes against theory so must question accuracy & reliability. Suggest improvements & developments in order to properly fulfil aim. - If contradicts theory why? - Personal geographical development stemming from reaching aim 4. Location Where description and map Why positives and negatives table Beenleigh Harbourne Head Bow Bridge Harbourneford Rolster Bridge Palmer Dam Description of the location River Harbourne is located in South Devon and is a small tributary of the Dart river system Source is located on Dartmoor at 350m above sea level on granite outcrop. River flows in a south easterly direction for 22 km along the long profile before discharging into the Dart estuary. The sites were selected for the combination of practical/ health and safety reasons and geographical reasons Location Potential questions: reasons for choice/ importance of choice in relation to aim/ relevance to theory or aim/ why appropriate. IMPORTANT TO CHOOSE A LOCATION WHICH PROVIDED THE CONDITIONS FOR US TO SAFELY & EFFECTIVELY UNDERTAKE AN INVESTIGATION INTO BRADSHAWS THEORY APPROPRIATENESS IS BASED UPON HOW WELL THE LOCATION ENABLED US TO CARRY OUT THE INVESTIGATION INTO BRADSHAWS MODEL RELEVANCE TO THE THEORY OR AIM IS MEASURED BY WHETHER THE LOCATION PROVIDED THE CONDITIONS NECESSARY TO CARRY OUT THE INVESTIGATION INTO BRADSHAW IN ORDER TO FULFUL OUR AIM ACCURATELY AND SAFELY Location Make sure that you can draw an annotated sketch map of the drainage basin showing the location Location Positive & Negatives of Harbourne PositivesNegatives REASONS: - Accessibility footpath & B-road nr. Dartmoor - Safety upper course = shallowest, narrowest, least fast flowing - Typical upper course = suitable for testing Bradshaw. Typified upper course, Bradshaw based on the perfect river. Needed upper course to be textbook e.g. v-shaped valley sides, would then be able to test Bradshaws theory effectively. - Proximity to field studies centre = availability of equipment - Average rainfall in Devon area - Not affected by human activity nearest settlement ?km downstream - National Park legal permission - Safe terrain studying OS map, could see that it was not too steep Only ?km of upper course not representative of whole river which is what Bradshaw theorises not suitable for theory, conclusions narrow Restrictions on locations due to accessibility Only very shallow Only used data from a few locations broader, more significant results if had chosen more points either further downstream or along upper course of similar rivers Rocky outcrops affected variables Potential questions: describe & justify/ evaluate Need to mention steps before & during: Risk assessment grid before (before so could be aware & prepare/familiarise with risks to avoid) involved us studying the OS map = also beneficial for our awareness of the area & hazards within What we did to prepare e.g. packed spare clothes in case of fall, stop hyperthermia wore sturdy footwear reduce risk of trips & slips wore waterproofs reduces likelihood of hyperthermia as stay dry Continuous monitoring during e.g. weather conditions/ water levels/ temperature/ human risks. 6. Data collection HOW Name the variable Name the equipment Name the units Draw it Strengths and limitations Do this for CSA and discharge Width X DepthCSA X Velocity 8. Data Presentation (Scatter Graph) Potential questions: evaluate effectiveness/ evaluate alternatives/ assess usefulness/ how did the aim or results influence Clear visual representation of relationship between 2 variables Esp. with distance on x axis: illustrative representation of downstream change in R. Harbourne useful & effective for drawing conclusions to aim Data continuous needed scatter graph The need to see relationship for these 2 variables to meet aim influenced choice Allows for line of best fit could see needed statistical test as line hard to draw Effective at communicating main info necessary to reach conclusion for aim Anomalies easily identifiable - useful Useful for easy data extraction Could only compare the 2 variables Not statistically verifying may see correlation, but need statistical test to confirm For better effectiveness, could be located to give precise conclusions for aim Could have compared 2 variables with another e.g. depth/width/velocity on a triangular graph Negatives of method Positives of method 9. Analysis Interpretation Spearmans Rank Potential questions: how & why useful for geog understanding/ appropriateness for data & aim/ justify use Appropriate: Uses data sets Had 2 variables which we wanted to statistically verify a correlation for Continuous data with a relationship Helped to achieve our aim: assess relationship between discharge & distance statistically Fact that it confirmed null hypothesis = helped to develop geog understanding as then had to return to data/maps/previous data/data from other rivers to understand why we achieved this result turned out to be rocky outcrops helped further understanding of external influences on river processes Justifiable: 10 data sets, continuous data, 2 corresponding variables, gave us the results needed to conclude our investigation & develop our conclusions to understand why 10. Conclusion There were a wide range of limitations that reduced the value of the enquiry, when quoting these for an exam question, you must quote their impact on the results: Inaccurate equipment such as the flow meter Difficulties in controlling variables such as the flow being diverted due to people standing in the channel. Human bias when collecting data for sediment size. Only a small section of the river was sampled The river was only sampled at one time of year. A number of improvements could be made to the investigation: Purchase new, more accurate equipment. Alter the sampling method to control variables more effectively. Extend the study be returning to the same sites at different times of year (different discharge expected). Sample different sections of the Harbourne, to analyse changes along the rivers course. Evaluating the techniques used Technical problems, e.g. Hydro-prop/ Impellor there are sometimes problems with equipment such as the hydro-prop. Its impellor sometimes will not rotate in slow moving water. An alternative measure of velocity, equated by using the time taken for a dog biscuit float to move along a stretch of stream 5 m either side of the site, was sometimes needed. Several recordings (e.g. 5) like this can be taken, to obtain a more reliable mean-average. This low-tech method can also encounter problems. Weeds or rock obstructions can stop the float and render the measurement worthless. It must also be remembered that this particular float method gives velocity for the surface flow, which is always slightly lower than the maximum velocity which takes place just below the surface. Human error can make the results unreliable, for example, if the velocity measurer stands upstream of the measurement, he or she can disrupt the flow and therefore change the velocity of water. It is also potentially easy to wrongly measure some of the variables, e.g. channel width (as it is difficult sometimes to precisely identify the top of the rivers banks). Health and safety requirements (e.g. safe access from surrounding land in to channel) dictate the location of sites, to an extent, which is an inevitable limitation to how representative the data is. An improvement to this enquiry would be to gain velocity measurements from different points across the cross-section of the stream (e.g. 5 points), if time and technology permitted (however the hydro-prop doesnt work in very low flow conditions, which are more likely away from the centre of the stream). A greater range of sites could be assessed, if time and resources (e.g. people involved/ equipment) permitted. For example 2 sites at each order of stream could be selected, doubling the number of stratified sample locations to six and the total number of specific sites (sampled systematically at 20 m intervals) to 30, providing more representative/ reliable data. Annotated sketches of the sites would be an excellent compliment to this enquiry, as parts of the sketch and its annotations could highlight/ emphasise expected explanations for characteristics, including possible anomalies, which might otherwise be overlooked by just recording the numerical data. Evaluation Potential questions: evaluate success/ usefulness for geog understanding/ evaluate in light of its aim & theory/ investigation development/ understanding theory/ use of secondary data to develop conclusions/ usefulness of conclusion & implications Success: Safely reached the aim of our investigation While results were unexpected, could explain why using secondary data e.g. OS maps & previous data Helped to develop our geog understanding of river processes & external factors e.g. rocky outcrops, which affect them: now understand better the processes affecting discharge, thus have better understanding of geog theory Location successful safe, easy to investigate & access Results may be useful for: the local authority e.g. council in town planning if want to expand Little Stretton; farmers to protect livestock; EA for flood management. However, successes limited Negatives & Improvements: Only 2km of upper course: not representative of whole river, does not parallel Bradshaw as he covered whole long-profile investigation needs extending Some methods inaccurate & unreliable: should have used GPS for sampling & digital flow metre/hydroprop for velocity measures too much human error & natural influence Only did 1 investigation did not repeat/take previous data/data from different seasons may just have been an anomaly 500m stretch missed due to health & safety Systematic sampling may have caused to miss important sites between the 100m points Needed more data, more accurate & reliable data & more locations & time periods to make investigation successful & useful The aim of our fieldwork was to see how various river characteristics change as we move downstream from the source. One such characteristic is discharge. Our hypothesis relating to this is as distance downstream from source increases discharge will increase. By investigating this hypothesis, we are investigating one of the river characteristics that the theory says will change as you go downstream. It will also tell us about related properties such as cross sectional area and velocity. The geographical theory that underpins our fieldwork is that river discharge increases as we move downstream from source to mouth. Discharge is cross sectional area times velocity. So discharge will increase if velocity and cross sectional area increase. Cross sectional area increases down stream because more tributaries enter the river adding more water which means the river is deeper and wider (cross sectional area is equal to width times average depth). This is due to the fact that downstream the river has drained more of the drainage basin. Velocity should increase because as the river gets wider and deeper and the sediment size gets smaller there is proportionally less friction through turbulence. The result is that water flows more efficiently and so faster. It should be fastest coming out of the upper course. State the main aim of a fieldwork investigation that you have undertaken. State a hypothesis or research question that you set up and explain how this helped you to achieve your aim. (3) Explain the geographical concept, process or theory that underpinned your fieldwork enquiry. (4) Our hypothesis was that as distance downstream from source increases velocity will increase. Using maps we identified suitable locations using systematic line point sampling (because we expected to see a pattern emerge with increased distance downstream) At each location we measured ... We did this at every sample point. The first limitation of our chosen method related to the sampling points. In particular, we did not stick rigidly to the method of systematic line point sampling. Instead we sampled at places where we could gain access to the river (i.e. places with car parks, bridges and footpaths). When we got to the sample locations there was no system as to what exact location we measured at. Downstream where the river was deeper it may have meant subconsciously looking for shallow locations, which shows a degree of bias. We may also have selected locations where there was a faster flow and a clear run, when focusing on velocity, in order to get the data collected quicker. When measuring thelength of river channel the tape was not straight and measuring the time less than precise. State one hypothesis or research question or issue for evaluation that you have investigated. Describe one method of primary data collection used in this investigation (5) Discuss the limitations of your chosen method in 2aii (above question) (6) The main technique we used to analyse the relationship between two variables was Spearman Rank (SR). We put our paired data in a table. We then ranked the data collected for each variable and calculated the difference in rank between each pair. The differences are squared (to get all positive values), totalled and then put into a formula, which gives us a coefficient (c). SR is a statistical technique which removes the need to interpret the data in a personal and subjective way. Rather, by plotting c on a significance graph, we can immediately see the nature, strength and level of significance of a relationship between two factors. The level of significance determines how confident we are in making conclusions from the results. SR can be used as a next step after a scattergraph has visually shown the relationship between the variables. Outline and justify the use of one or more techniques used to analyse your results (5) We chose to represent our data using .. which would make the results easy to see when displayed. On the computer we . This method allows visual synthesis of the information and provides an at a glance way of spotting patterns, because it is highly visual. So it is possible to visually test theories between cross sectional area and distance downstream. Any suspected relationship could then be further investigated using a scattergraph and then Spearman Rank. It also allows other results (like sediment size) to be presented alongside the cross sectional area which might help explain related characteristics such as velocity. Describe one technique that you used to present your data. Explain why this was an appropriate technique to use (7) Drawing upon your findings, explain how your enquiry improved your understanding of the topic (5) The Spearman rank correlation coefficients (c) for distance downstream (dd) and discharge was XXXX. For dd and cross sectional area (xsa) it was XXXX Both results are significant at the 0.05 level. Dd and velocity produced a result of 0.46, which is not significant at any level. So overall, discharge (which is xsa x velocity) significantly increases as dd increases. This is mainly due to the strong increase in xsa downstream. This in turn takes place because of all of the tributaries entering the main channel, draining as they do additional parts of the drainage basin. This additional flow will mean the main channel becomes deeper and wider and so xsa increases. Velocity does not increase so strongly. Part of the reason may be due to the gentler slope gradient downstream. So while the channel roughness and hydraulic radius may work to increase velocity, the gentler slopes work against it. So velocity increases less well. The main risks associated with our rivers based fieldwork related to the water itself. We were forewarned about slippy, moss-covered rocks and instructed to tread slowly and carefully to the side of them where possible. We entered the river where there was a gently sloping bank, to avoid the prospect of bank collapse and resulting injury. Identifying these prime dangers meant we were confident in entering the water and successfully avoided any injury. The other main risks related to travel to each site. Seat belts reduced the risk in the mini bus and vigilance when crossing access roads meant that major injury was avoided. Before visiting an area for fieldwork, a risk assessment must be completed. Outline the risks associated with carrying out the fieldwork and assess the effectiveness of strategies used to minimise the risks. (5) Describe one application of ICT skills in carrying out your fieldwork and comment on its usefulness. (5)