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选取东柳沟流域作为研究区域,通过分析主河道中泥沙颗粒的粒径特征,研究流域沉积物的分布规律及其粒径变化过程。应用激光粒度仪对研究区内的河道沉积土样进行测定,使用秩和检验对泥沙颗粒特征进行分析,得到流域沉积泥沙粒径分布及变化规律。结果表明,根据中值粒径和河道比降的变化,将东柳沟流域分为丘陵区、沙丘区和农田区3个区域。流域沉积泥沙的中值粒径从上游丘陵区到下游农田区逐渐呈减少的趋势。3个分区的沉积泥沙级配特征有显著不同,丘陵区的沉积泥沙主要由粗沙构成,极粗沙和中粗沙约占57%。而沙丘区和农田区以细沙为主,且越往下游细沙含量越大,其中沙丘区沉积物中细沙及更细的颗粒所占比例约为64%,农田区沉积物中细沙及更细的颗粒所占比例约为84%。据此表明,东柳沟的侵蚀过程在空间上表现为水力侵蚀和风力侵蚀作用的交替叠加,其中沉积泥沙中值粒径变化最剧烈的地方是风蚀和水蚀交错最为频繁的区域。
The Dongliu River Basin is chosen as the research area. Through the analysis of the grain size characteristics of the sediment in the main channel, the sediment distribution and the variation of the grain size are studied. The laser sedimentometer was used to determine the sediment samples in the study area, and the sediment particle characteristics were analyzed by rank sum test to get the sediment particle size distribution and variation law. The results showed that according to the change of median diameter and river ratio, the Dongliu River valley was divided into three areas: hilly area, dune area and farmland. The median sediment sediment sediment median grain size from the upper reaches of the hilly area to downstream farmland area gradually decreased. Sediment sediment distribution characteristics of the three sub-areas are significantly different. The sediment sediment in the hilly area is mainly composed of coarse sand, which accounts for about 57% of the coarse and coarse sand. While the sand dune area and the farmland area are dominated by fine sand, and the more the sediment content of the downstream reaches is, the proportion of fine sand and finer particles in the sediment of the dune area is about 64% And finer particles accounted for about 84%. The results show that the erosion process of Dongliugou is spatially represented by the alternating superimposition of hydraulic erosion and wind erosion. Among them, the most frequent change of sediment median diameter is the area where wind erosion and water erosion are interlaced most frequently.