Study Figure 1a and Figure 1b.

A group of students investigating a coastal spit expected:

• mean pebble roundness (Cailleux Index) to increase as sediment was transported eastward from the start of the spit (Site A) to the distal end (Site F)
• beach gradient to decrease as distance from the start of the spit increased

After analysing Figures 1a and 1b, the students concluded that changes in pebble roundness were more in line with their expectations than changes in beach gradient.

Assess the extent to which you agree with this conclusion.

Figure 1a & Figure 1b

Draw on this

Data for Figure 1a

Data for Figure 1b