Flux and Particle Size Characteristics of Landscape Sediments in a Desert Riparian Forest Along Lower Reaches of Tarim River

[Objective] The characteristics of sand and dust transport amount and particle size on the windward and leeward sides of a natural Populus euphratica riparian forest at the Arghan section of the lower reaches of the Tarim River under the prevailing wind direction were studied in order to provide a theoretical basis for its windbreak and sand fixation capacity. [Methods] Sediments were collected from two windward sites (Y1 and Y2) and two leeward sites (B1 and B2) of the forest at five heights of 10, 30, 50, 100, and 150 cm near the surface using a BSNE sand collector. The particle size characteristics of the sand samples were then measured using a Microtrac S3500 laser diffraction particle size analyzer. [Results] ① The horizontal flux of sand and dust in the four sample plots followed either a power function or exponential function distribution, and total sediment transport followed the order of Y1 > Y2 > B1 > B2. The sediment transport for each sample plot decreased with increasing height from the soil surface. ② The reduction of sediment on the leeward side compared with the windward side ranged from 35% to 80% less than on the windward side, indicating that the natural P. euphratica riparian forest in the lower reaches of the Tarim River has obvious windbreak and sand fixation benefits. ③ The average particle size of sand grains at all heights was 80~93 μm, mainly composed of extremely fine sand. The particle size frequency curve showed a single peak distribution, and the sand dust composition was simple, mainly composed of local sand sources. [Conclusion] The sediment transport on the leeward side of the natural P. euphratica riparian forest in the study area was lower than that of the windward side. Average particle size was smaller and sorting performance was better on the leeward side than on windward side. The average particle size smaller than that of the windward side, the sorting was better than that of the windward side, the kurtosis was narrower than that of windward side, and skewness is slightly smaller than that of the windward side. The P. euphratica riparian forest exhibited obvious windbreak and sand fixation benefits, and can be used as an effective measure to reduce the damage by wind and sand transport in the study area.