Sediment plume development from forest roads: How are they related to filter strip recommendations
Forest roads have been presented as the major source of soil erosion from forestactivities in recent years. Controlling sediment movement from forest roads is emphasizedin forest management throughout the nation. However, design and development of BestManagement Practices (BMPs) to control sediment movement from the forest road prismrequires a better understanding of the factors influencing sediment transport distancesdownslope. Relationships developed specifically for national forests will give managersadditional planning and evaluation tools for roads and can be used to assess the potentialfor environmental impacts on existing forest roads. The USDA Forest Service SouthernResearch Station, Forest Operations Research Unit, initiated a study to evaluate factorsinfluencing sediment plume development downslope of forest roads on national forests inAlabama and Georgia. A total of 235 sites were measured based on replications ofdownslope gradients, road gradient classes, soil textures, and forest floor indices. The datawere used to develop a prediction equation based on site specific characteristics. Roadcharacteristics (road section length and road width) had the greatest influence on thedistance sediment traveled downslope from forest road lead-off ditch outlets. Generally,visible sediment plume development extended less than 90 m.