Location description
The study will take place at the Mulunguzi river in Zomba. Zomba is a small town in which a plateau is located—it is on this plateau, at 15▫ south and 34▫ east, where the source of the river Mulunguzi is found. The river is perfect to carry out this investigation as it enables us to examine a number of its features including: meanders, waterfalls, rapids, tributaries and so on. Zomba plateau is also easliy accessible for us, being only an hour away from our school in the city of Blantyre. The location of Zomba Town and the Zomba Plateau can be seen on the following maps.
Analysis and Conclusion
Are my hypotheses correct? Do they apply to the Mulunguzi river?
1.“The width of the river channel will increase with distance downstream.”
The general pattern of graph figure 3 on page 7 which shows the widths of the river at each site does infact agree with the hypothesis as it shows that after site 1, the widths did increase. One exception was at site 4. At site 4, the river is wider than you would expect as it flows over hard rock which is not so easily eroded and so flows over a wider area. There isn’t a big difference between the widths of the river at the various sites because they weren’t very far apart. The difference in width between site 1 and site 8 is only 6.4 m. I would expect however that further down the river, towards the mouth, the river would get much wider.
2.“The bedload shape( smoothness and roundness) should increase with distance downstream”
3.“The cross-sectional area of the river channel increases with distance downstream.”
The original aim of the coursework was to identify how and why the river Mulunguzi’s characteristics change downstream. From the upper course through to the middle course of the river, due to the changing velocity and energy, different types erosion occur shaping the features of the river e.g as my results show that the width increased further down along the river which was due to more lateral erosion occuring downstream as well as more hydraulic power erosion, and the roundness of the bedload increased due to more attrition making the rocks collide and become smoother towards the middle course.
Evaluation
I think we could improve the investigation by:
- Collecting our results at different times of the year. This investigation was carried out in summer just before the heavy rains were there would have been a greater volume of water flowing in the river and so the results would vary in different seasons.
- Being provided with more equipment. We were working in groups of about 4 and there wasn’t always enough equipment to go around for each group to use. For example at one point our group had to measure the width of a certain site using only a meter ruler which might not have given us accurate results.
- Choosing different sites that are further apart as there was not a great deal of variation in the results between the sites. The changes in the width for example, between the sites could be more significant if the sites were further apart.
I could improve my presentation techniques by:
- Creating two or more separate graphs to show the cross-sections of the river. It would be easier to read the graphs this way and clearly distinguish between each cross-section.
- Including more varied and complicated graphs.
- Including a better map of the zomba plateau showing the locations of the different sites we visited. Unfortunately the only map I could find showed the plateau completely covered by clouds.
