Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

A storm runoff simulator is needed to evaluate conservation buffers having field to buffer area ratios (BAR) greater than 30:1, the minimum design criteria specified by the NRCS. To evaluate a range of buffers in a field setting, a simulator was proposed that would be compatible with buffer design criteria of 100:1 BAR, 6 m width and 7.5 m plot length, and soil and water handling constraints of 1 ton and 63 L s-1, respectively. Based on an engineering analysis using RUSLE and HEC2, it was determined that a simulator could be developed for a 1 x 9 m buffer given resource constraints of 7,580 L stored water and 7.3 L s-1 peak flow rate for BARs greater than 30:1. A hydrograph simulator that operates under gravity flow and uses a feedback control system between an actuated valve and flow meter was designed, built and tested. A time-compressed 10yr- 2hr SCS design hydrograph with a 7.3 L s-1 peak flow rate was used to calibrate the simulator for optimal performance with large changes in flow rate and for compatibility with a variety of hydrograph shapes. When reproducing the compressed SCS hydrograph, the simulator maintained comparable efficiencies among repetitions, with a 2% error between root means square error and the total flow range. Hydrographs with step changes in flow rate, flow rate plateaus, multiple peaks and flow rates up to 9.8 L s-1 could be reproduced with comparable efficiencies and 4 to 6% error.