风蚀水蚀共同作用下沙漠河流泥沙级配特征

以水蚀风蚀区内蒙古河段重要入黄支流西柳沟为研究对象，通过对西柳沟流域产沙地层及河流水文站悬移质泥沙采样分析和激光粒度仪测定，对研究区河道纵向、横向断面沉积的泥沙级配特征进行了分析，揭示了流域沉积泥沙粒径分布变化规律。结果表明：西柳沟流域沉积泥沙的中数粒径从上游丘陵沟壑区到下游农田区逐渐减小；河流右岸泥沙粒径较大，左岸泥沙粒径相对较小，河床泥沙粒径介于二者之间；流域沉积泥沙粒径主要分布在0.125~0.5 mm，而流域出口水文站悬移质泥沙粒径72.5%在0.025 mm以下，说明西柳沟进入黄河干流的泥沙主要为细泥沙。

Sediment Particle Size Distribution Characteristics in a Desert Gully Influenced by Coupled Aeolian and Fluvial Processes

Using sampling and laser particle analyzer, the suspended sediment load of was studied in the Inner Mongolia Xi Liu Gou reaches of Yellow River. The characteristic of the depositional sediment size distribution of transverse and longitudinal sections were also analyzed, and then the regularity of depositional sediment particle size distribution was revealed. The results showed that the sediment deposited of median particle diameter displayed a decreasing tendency from the up-stream hilly-gully region to downstream farmland area. The sediment diameter on right bank of river was bigger than that of left bank; the sediment article of riverbed was between that of right and left. The sediment particle sizes of the valley are mainly distributed in the range of 0.125 mm to 0.5 mm, but there was 72.5 percent of suspended sediment particle sizes under 0.025 mm in the basin export hydrological station, this revealed that the sediment from Xin Liu Gou valley to mainstream of Yellow River was chiefly the fine grain-size fractions.