Final answer:
Cliff erosion sediment source can be reduced through erosion control measures, restoration of natural habitats, and reduction of human activities.
Step-by-step explanation:
Cliff erosion sediment source can be reduced by various factors. One way it can be reduced is through the implementation of erosion control measures such as the construction of seawalls or breakwaters, which can help protect the cliffs from wave action and prevent sediment from being eroded. Another way is through the restoration of natural habitats and vegetation on the cliffs, as plants help stabilize the soil and reduce erosion. Additionally, reducing human activities that contribute to cliff erosion, such as over-extraction of sand or gravel, can also help reduce sediment source.