Which of the following is a potential issue related to slope stability?

Settlements due to poor fill are a significant concern when it comes to slope stability. When fill material is not correctly placed or compacted, or if it consists of unsuitable materials, voids can develop, leading to differential settlement. This can destabilize slopes, create fissures, and ultimately lead to landslides or slope failures.

Addressing soil fill quality is essential in construction and engineering practices, as poorly managed fill can result in inadequate support for structures and environments. Ensuring proper compaction techniques and suitable material selection can mitigate these risks, but once settlements occur, they can have serious implications for the overall stability of a slope.

In contrast, the other options, while relevant to certain aspects of soil and structural integrity, do not directly address potential slope stability issues in the same way as concerns regarding settlements from poor fill.