This project aims to make you think hard about a set of geographical data and to develop three research questions or hypotheses using the deductive approach of the scientific method that relate to these data. You are provided with an Excel spreadsheet of data which relate to controls of fluvial denudation rates in the major world drainage basins (see
map).
Denu.xls
Why are we interested in denudation rates? Firstly, estimates of global denudation (chemical and mechanical) rates provide important inputs to quantitative models of landscape development. Secondly, they provide an insight into the extent that global tectonics may influence landscape development. And finally, they provide useful information for those interested in calculating mass sediment balance estimates.
The dataset contains information about solute and mechanical denudation rates, as well as other variables relating to each basin for which data are available. This dataset is not large, yet it contains information from basins that effectively cover 35% of the Earth's surface. This is an important point for you to consider in your analysis.
Your task is as follows:-
1. The
dataset contains information about solute and mechanical denudation rates, as well as other variables relating to each basin for which data are available. This dataset is not large, yet it contains information from basins that effectively cover 35% of the Earth's surface. This is an important point for you to consider in your analysis.2. Go away and do some reading and thinking on controls on denudation rates. There are many useful sources in the basic physical geography text books, but Summerfield, M.A. (1997) Global Geomorphology (Chapter 15) is a good start (and references therein).
3. Before returning to the spreadsheet, do some serious thinking. Develop some initial ideas about what variables you believe may be controlling denudation rates.
4. Return to the spreadsheet and explore the variables more thoroughly.
5. Develop three research hypotheses that relate to the possible controls on denudation rates. Each hypothesis should be short and simple – 20 words or less. For each hypothesis also provide a statement as to why you believe this to be an important scientific question and also on what additional data, if any, you feel you might need to test the particular hypothesis.
6. Your typed report, with three hypotheses clearly defined and justified, should take up no more than 2 sides of A4, with a font size of 12. This report should be handed in to the Department Office by November 22 2000.
7. Remember that you are being asked to develop three research hypotheses, not to test them.
Things to Think About
The dataset provided in based on information thought to be unaffected by human activity, so you can dismiss processes such as recent large scale deforestation as a possible impact on regional variations in denudation rates.
These variables include both responses and controlling variables and on long time periods there are feedbacks between different variables. For example, erosion will, eventually, influence relief and hence precipitation.
Also, think carefully about the size of the basins under analysis. Are all the basins the same size? Are they all large, intermediate or small in size. Are they evenly distributed across the Earth's surface?
You are provided with a single estimate of each variable for each basin. How appropriate is this?
Assessment
This is an open-ended practical in the sense that there is no right or wrong way to complete the task. Your work will be assessed for the intelligence of the questions asked, your ability to define how the hypotheses will be tested and, where appropriate, your understanding of what other data you would require or what methods you would use to test the hypotheses proposed.