The movement of spray drift near a live shelterbelt

Abstract

There has been recent interest in the use of shelterbelts to mitigate spray drift and protect downwind areas. Previous research has investigated the interaction of spray drift and shelterbelts using model shelterbelts, wind tunnel experiments, and numerical modeling; however, there is limited knowledge on the movement of spray drift near a live shelterbelt in field conditions. These experiments measured the ground deposition and airborne concentration of drift near a live carragana/chokecherry mix shelterbelt. It was found that when compared to open field experiments where there was no shelterbelt, the mass of ground deposit was less in the lee of the shelterbelt for a distance of 0-10H downwind of the shelterbelt (where H is the height of the shelterbelt). Further than 10H downwind of the shelterbelt, the mass of ground deposit was similar to the open field. There was an 88% reduction in airborne drift exiting the shelterbelt as compared to the drift entering the shelterbelt, which likely caused the reduction in deposition in the shelterbelt’s lee. It was shown that there was a larger proportion of drift diverted over the top of the shelterbelt as compared to the drift exiting the shelterbelt. Although not apparent in these experiments, this suggested that there may be increased deposition further downwind from the shelterbelt as compared to the open field.