What does sediment yield measure?

Sediment yield specifically measures the amount of eroded soil that is transported and delivered to a designated point within a watershed. This concept is critical in watershed management, as it helps to understand the processes of erosion and sediment transport, which can significantly affect water quality and aquatic habitats downstream. High sediment yield can lead to problems like water pollution, degradation of habitats, and increased costs for water treatment.

The other options relate to different aspects of environmental management but do not capture the essence of sediment yield. The volume of planting materials used pertains to landscaping or restoration efforts and doesn't reflect soil erosion dynamics. The rate of surface runoff during heavy precipitation is related to water movement rather than soil displacement. Lastly, the frequency of flooding relates to hydrology and weather patterns, which again does not address the measurement of soil erosion and transport. Thus, the correct focus on sediment yield as the amount of eroded soil arriving at a watershed point underlines its importance for both environmental assessment and management practices.