What factor describes the susceptibility of soil to be moved by running water or wind?

Erodibility is the factor that specifically describes the susceptibility of soil to be moved by running water or wind. It refers to how easily soil particles can be detached and transported by erosive forces, such as flowing water or wind. This characteristic is influenced by several soil properties, including texture, structure, vegetation cover, and moisture content. Highly erodible soils, like sandy soils with little vegetation, are more prone to erosion compared to clayey soils, which tend to hold together more firmly.

The other choices involve different aspects of soil behavior and characteristics. Upland refers to areas of higher elevation but does not indicate erosion susceptibility. Compaction describes the density of soil and its ability to resist movement, which can affect erosion indirectly but does not define susceptibility. Permeability relates to the ability of soil to transmit water, affecting drainage but not the direct mobility of soil by erosive forces.