We were taken to an area of the desert approximately 20 kilometers
inland from Jeddah. On arrival, we were asked to carry out practical
investigations of the landforms and landscape in the immediate area,
in order to find evidence of river processes and resulting landform
such as erosion, transportation, weathering and depostion . these
investigations took place in a valley (“wadi”), which is an
intermittent watercourse, during the dry season. To carry out our
measurements, we devised the following equipment before hand:
* A clinometer, to measure the gradient along the “wadi” and its
cross profile (long profile).
* A stone board, in order to measure the size of rocks
* A chart to classify the chosen rocks
* A quadrate to help choose rocks randomly
Before leaving to the “Wadi”, we prepared a list of hypotheses. Our
aim was to prove or disprove them after collecting and analyzing our
1. the stones found at the top of the “wadi” are larger then those
at the bottom
2. the stones found at the top of the “wadi” are more angular than
those at the bottom.
3. the slope at the top of the “wadi” is “v-shaped”.
4. the slope at the bottom of the “wadi” is “u-shaped”.
5. weathering is more common at the top, as there is more exposure.
6. the angle of cross section will be smaller where the load is more
7. there is evidence of attrition taking place.
8. the smaller the stone the more rounded it is.
9. the larger the stone the more angular it is.
10. there is evidence of exfoliation (onion weathering) because of
weather condition in the desert.
11. the gradients will be greatest in the upper course and lowest in
the lower course
12. interlocking spurs can be seen
13. there is evidence of deposition in the lower course and near
14. there is the most evidence of erosion on the stones in the lower
15. there are sign of vegetation along the course of the river
16. the angle of the cross section will be smallest in the upper
course and greatest in the lower course.
17. the load in the lower course will be small and rounded.
18. corrasion will occur more in the...