soil conditioner

This graph describes the relationship between stream flow velocity and particle erosion, transport, and deposition. (Source: PhysicalGeography.net) Figure 2: This graph describes the relationship between stream flow velocity and particle erosion, transport, and deposition. (Source: PhysicalGeography.net) The main force reponsible for entrainment is fluid drag. The strength of fluid drag varies with the mass of the eroding medium (water is 9,000 times more dense than air) and its velocity. Fluid drag causes the particle to move because of horizontal force and vertical lift. Within a medium of erosion, both of these forces are controlled by velocity. Horizontal force occurs from the push of the agent against the particle. If this push is sufficient to overcome friction and the resistance of cohesive bonds, the particle moves horizontally. The vertical lift is produced by turbulence or eddies within the flow that push the particle upward. Once the particle is lifted the only force resisting its transport is gravity as the forces of friction, slope angle, and cohesion are now non-existent. The particle can also be transported at velocities lower than the entrainment velocities because of the reduction in forces acting on it. The critical entrainment velocity curve suggests that particles below a certain size are just as resistant to entrainment as particles with larger sizes and masses (Figure 2). Fine silt and clay particles tend to have higher resistance to entrainment because of the strong cohesive bonds between particles. These forces are far stronger than the forces of friction and gravity. Once a particle is entrained, it tends to move as long as the velocity of the medium is high enough to transport the particle horizontally. Within the medium, transport can occur in four different ways: Figure 2: This graph describes the relationship between stream flow velocity and particle erosion, transport, and deposition. (Source: PhysicalGeography.net) Figure 2: This graph describes the relationship between stream flow velocity and particle erosion, transport, and deposition. (Source: PhysicalGeography.net) * Plucking: ice freezes onto the surface, particularly in cracks and crevices, and pulls fragments out from the surface of the rock.