Use of Grass Filters for Sediment Control in Strip Mine Drainage. Volume 3. Empirical Verification of Procedures Using Real Vegetation

摘要

The objective of this research was to develop a prediction model capable of estimating outflow sediment concentrations and fractions of sediment trapped for a vegetal filter based on the inflow conditions and filter dimensions. The method of study was to base the model on relationships which has been developed using simulated, rigid media with stead flows and modify these equations so they can be utilized to design filters for field conditions. The basic prediction model was first validated for the unsteady flow, homogeneous sediment case using simulated vegetation. Laboratory work was then conducted to characterize the dimensions which are required inputs for the model for three types of grass. Limited deposition data were collected in a short flume, using real grasses. Results indicated that the average error with which fractions of sediment trapped could be estimated was less than 0.05. The vegetative filter prediction model was concluded to be adequate and satisfactory for use in most design work.