Design of erosion control materials for life-time performance

Effective erosion control depends on numerous and, often, time-dependent inputs, including soil type, rainfall intensity, volumetric runoff, vegetative cover, and seasonal conditions. Clearly, several of these inputs can change over time. Therefore, the appropriate design of erosion control systems must consider the changes which take place within the erosion control system over time. Specifically, as vegetation becomes increasingly established, the role of the erosion control material changes. Some materials may be more effective initially than after vegetation is established and vice versa. This paper presents a comprehensive design technique which considers both unvegetated (bare soil) and vegetated conditions, and suggests how both of these conditions may be considered with respect to time for a single site. The design technique relies on performance test data and makes use of generally accepted design tools such as the USLE and tractive shear calculations. Guidance is given on completely identifying the life cycle erosion control requirements of the project and designing accordingly to satisfy both short-and long-term project requirements.