Abstract View
Impact of Forest Belts on Reducing Desert Dust Concentration in Urban and Suburban Areas
OFIR VADAS, Boris Krasovitov, Andrew Fominykh, Avi Levy, Itzhak Katra, Ben-Gurion University of the Negev, Israel
Abstract Number: 113
Working Group: Urban Aerosols
Abstract
Numerous studies show that exposure to fine dust particles transported in the atmospheric surface layer during dust storms increases the risk of exacerbation of various bronchopulmonary and allergic diseases in humans. Applying of planted forest belts (windbreaks) reduces airborne dust during dust storms, resulting to healthier atmosphere in urban and suburban environments. This study investigated the impact of forest belts on the spatial distribution of PM10 concentration following dust events in a region that is subjected to frequent dust storms. The developed model considers the interaction between the open area on the windward side of the windbreak, and windbreak aerodynamics. The two-dimensional model is based on the application of theory of turbulent diffusion in conjunction with model of dust particles deposition on vegetation elements. The initial wind velocity profiles, used in the simulations were fitted from data obtained in field measurements in the studied region. Numerical simulations are performed for windbreaks, which consists of planting pine trees (pinus halepensis) typical for northern Negev region, Israel. Using the developed model, a numerical simulation of the dust transport through windbreaks of various porosities and widths was carried out. In particular, numerical analysis was performed for highly porous windbreaks with widths 1.25H and 2.5H, where H is the average height of the windbreaks. Results of calculations showed that during high-level dust storms at the leeward side of the windbreaks PM10 concentrations are reduced by 14% and 20% correspondingly. It has also been shown that the use of windbreak strips can reduce the PM10 concentration by 6-8% even at a considerable distance (about 1 km) from the windbreak. The results of this study emphasize the importance of planted semi-arid forest belts for controlling air pollution in the adjacent urban areas by reducing PM concentration in the atmosphere during dust events.