The Effectiveness of the Consolidated Desert Surface by Mixing of Fly Ash and Polyacrylamide in Wind Erosion Control

Abstract

This study evaluated the resistance to wind erosion of a consolidated soil layer (CSL) using an indoor wind tunnel under simulated wind erosion conditions. The CSL consisted of the experimental soil (classified as a sandy soil), fly ash (FA) at two addition rates (10 and 20 % (w/w) soil), and polyacrylamide (PAM) at two addition rates (0.05 and 0.1 % (w/w) soil). Prior to the wind tunnel experiments, according to the different addition rates of FA and PAM, the sandy soil, FA, and PAM were homogeneously mixed by spraying an appropriate amount of deionized water to form different CSLs. The moisture content of the CSL was balanced to that of the sandy soil in the field. The threshold wind speeds and wind erosion amounts of different CSLs at two wind speeds of 8 and 14 m/s were measured, respectively. The results showed that the threshold wind speed of the sandy soil was significantly increased due to the formation of CSL by FA and PAM, exhibiting an increasing trend with increasing addition rate of FA and PAM. The wind erosion amounts of different CSLs were all decreased when compared with that of the sandy soil. The resistance to wind erosion of the CSL consisting of 10 % FA and 0.1 % PAM was strongest at a wind speed of 8 m/s, while only slight wind erosion occurred after 30-min exposure to the wind with a speed of 14 m/s.