The implementation of ArcView GIS as a predictive model to determine erosion trouble areas along Little Westham Creek

According to the Virginia Department of Conservation and Recreation (1992), soil erosion can be defined as the process by which the surface of the land is deteriorated by the action of wind, water, ice, and gravity. The erosion generated by water is undoubtedly the most severe type of erosion produced and was therefore the focus of this research project- particularly the erosion that occurs as a result of suburbanization. Water-generated erosion can be broken down into five main types as outlined by the Virginia Department of Conservation and Recreation (1992) and are as follows: (1) raindrop erosion, (2) sheet erosion, (3) rill erosion, (4) gully erosion, and (5) channel erosion (Figure 1). Raindrop erosion constitutes the first effect of a rainstorm on the soil and involves raindrops actually striking the soil and dislodging soil particles into the air, thereby making these particles more susceptible to sheet erosion. Sheet erosion is defined as the erosion that occurs as the result of the shallow flow of water running over the surface of the land. Rather than serving as an instrument to detach soil particles, it instead transports soil particles that have been detached as a result of raindrop erosion. Rill erosion occurs as the shallow surface flow begins to accumulate in the low spots that result from irregular contours of the surface. The energy generated from rill erosion is greater and therefore is able to detach and transport soil, as well as cut small channels of its own. As the flow from the rills come together to form larger channels, gully erosion arises. Finally, channel erosion takes place as both the volume and velocity of flow initiates movement of the streambed and bank materials