黄河乌兰布和沙漠段沿岸风沙流结构与沙丘移动规律

为明确黄河乌兰布和沙漠段沿岸的风沙活动及沙丘移动特征,该文以黄河乌兰布和沙漠段沿岸的流动沙丘为研究对象,采用野外观测与实验室分析相结合的方法对沿岸沙丘的起沙风况、沙物质组成、风沙流结构及沙丘移动规律进行初步的定量研究。结果表明:起沙风的主风为西南—西风,集中于3-5月份,且5～6m/s风占起沙风的50.26%;沙物质粒径以细砂(0.1～0.25mm)为主,沿黄段沙丘粒径极细砂以下(≤0.1mm)的沙物质粒径组成比沙漠腹地减少8.92%;距地60cm高度范围内,81.75%的沙物质在0～10cm高的气层中通过。在沙丘的不同部位上,相对输沙量与高程之间有着良好的幂函数关系;沙丘向前移动的距离为8.19m/a,主要发生在3-5月份。该研究结果可为合理计算入黄风积沙量及完善黄河沿岸综合防护体系提供科学依据。

Structure of wind-sand flow and law of dune movement along bank of Yellow River in Ulan Buh desert

To understand the sand dune movement activities and characteristics in Ulan Buh desert along the Yellow River,taking the mobile dunes along the bank as study material and based on lots of work in the field observation and lab analysis,a primary quantity research was made to study the wind speed of sand raising,constituents of sand,structure of wind-sand flow and moving characteristics of dune movement.The results showed that the study area from the main sand wind WS-W,concentrated in March to May,and 5-6 m/s wind accounted for 50.26% of the wind-sand;Sand material particle size are mainly fine(0.1-0.25 mm);Along the Yellow River segment,the composition of sand dune particle below very fine size(≤ 0.1 mm) is 8.92% less than that of the desert hinterland.About 81.75% sand material of the study area pass through 0-10 cm air layer.There is a good power function relationship between the relative sediment discharge and elevation in different parts of the dunes;The dunes move forward a distance of 8.19 m/a,mainly occurred in March to May.The findings in the study can provide a scientific basis for calculating the amount of sediment in the Yellow River and improvement of comprehensive protection system along the Yellow River.