A device for simulating overland flow

A flow Simulation Applicator (FSA) was developed to create even-sheet overl and flow of water into a vegetative filter strip. The FSA, constructed from easily-obtained materials, is adaptable to various applications, portable, easily calibrated and delivers reproducible flow, rates. Variability among replications was quite small with Coefficient of Variability (CV) of less than 1.5%. Water flowed as a sheet onto the test surface at application rat es of 4 L min(-1) (1.1 gal) or greater. In initial field tests, the device runs used to apply a 0.1 mg kg(-1) (0.1 PPM) atrazine solution to 1 x 5-m ( 3.3 x 16.4-ft) sections of buffalograss (Buchloe dactyloides Nutt. Engelm.) sod at a rate equivalent to runoff occurring from a 30-m (98.4-ft) wide fi eld directly upslope with a 5.1 cm (2 in) rain. The outflow atrazine concen tration from the sad was reduced in the first 15 min, and then increased, s tabilizing at 85% of the input concentration. With minor modifications, the FSA can provide inflow for concentrated flow experiments.