Overland Flow and Soil Erosion

Soil erosion is complex and involves the detachment and transport of soil particles, as well as infiltration, ponding and runoff of rainfall. The magnitude and frequency of these processes is related to climate, rainfall characteristics, topography, soil characteristics, management practices, and scale. However, the full implications of dynamic properties of the soil and variability in inputs to the system have seldom been considered. Recent thinking suggests that at the field scale interactions between climate, cultivation practices, and soil properties have the dominant influence on soil erosion, but at the catchment scale runoff appears to be the main factor influencing overland flow and erosion. Understanding overland flow and soil erosion is a key problem for the future as land clearance, increasing intensification of land use and population growth tend to result in increased sediment delivery in river catchments, leading to problems of flooding, pollution and sedimentation.