Deposition of Aerially Released Bt Over a 2 Km Sampling Grid: Near-Field Model Comparison

摘要

A large area aerial spray trial was conducted to provide deposition data to evaluate a long range aerial spray modeling system that links the AGDISP and CalPuffmodels. This paper describes the experimental set-up and discusses results from near fieldarrays, comparing these to deposition predictions calculated using AGDISP. Seventeen live spray trials and three blank trials were conducted resulting in over 2200 deposition samples. Bacillus thuringiensis (Bt) was used as a tracer. Preliminary analysesindicate that AGDISP matches data reasonably well in the first 300m which is within the recommended domain of that model. There is, however, a marked tendency in some trials for AGDISP to predict a flatter deposition pattern with distance than is shownby the data causing the model to under-predict deposition near the swath and over-predict at 200-300m downwind.