Effect of Some Polymers on Soil-water Losses and Sediment Size depending on Initial Aggregate Size under Sequential Simulated Rainfall

AbstractEarth is quickly changing in physical meaning. Especially as a result of climate change, increasing number of swelling-shrinking cycles that managed by wetting-drying and freezing-dissolving events in the soil, closely affects the aggregate stability. Main purpose of this study is to research the effects of polyvinyl alcohol (PVA) and polyacrylamide (PAM) which are applied to different size of aggregates of a Typic Xerorthent on the runoff and soil losses under the sequential simulated rainfalls in the laboratory. Other purposes of this study are to research efficiency duration of polymers as part of the fragmentation dynamics and to determine particle size distribution in transported material. At the aim of the project diverse aggregate sizes of the soil were put in soil pans. PVA and PAM were applied on these aggregates. Simulated rainstorms with 360mm h-1 intensity were applied by using “Eijkelkamp rainfall simulator” for a duration of 12minutes. After 48hours first rain application, sequential simulates rainfalls were applied on same pans. Particle size distribution was partially determined in sediments. In the end of the study, while minimum and maximum runoff quantities (RQ) were measured as 11.9mm (in > 6.4mm aggregates + PVA) and 40.6mm under first rainfall, respectively, these values were measured in the same application pans as 22.6mm and 49.1mm under sequential rainfall. In the first rain event, soil quantities transported by runoff (SQTR) were ranged from 89.1 to 3923.1g m-2 above application pans. In the second rain event, SQTRs were ranged from 91.8 to 4739.4g m-2 same pans. According to particle size analysis results polymers were found successful to keep particles together under first rain event.AcknowledgementsThis study was supported financially by The Scientific and Technological Research Council of Turkey (TUBITAK). We thank the said institute. Project Code: TOVAG/113-O-555