内陆河三角洲堆积体形成发展过程

通过概化水槽试验对水流泥沙从内陆河进入浅水湖泊后的三角洲堆积体形成发展过程进行研究。试验结果表明,在平面形态上,三角洲堆积体的形成发展过程可分3个阶段:第一阶段,水流泥沙在初期依次按小沙波体、带状沙波体、扇形三角洲堆积体和舌状三角洲堆积体形态形成发展,堆积体表面无明显主河槽且两侧区域无串沟;第二阶段,水流泥沙沿堆积体表面河槽在左侧区域和右侧区域之间交替推进;第三阶段,水流泥沙沿新河槽在摆动中同步推进。在纵向推进中,第一阶段初始较大,受横向展宽影响逐渐减弱;第二阶段以相对稳定的速率交替推进;第三阶段呈减弱趋势,最终保持同步推进速率。在垂向上,堆积体以稳定的速率淤积抬高发展;在横向上,水流泥沙在河槽主流摆动中不断横向输移泥沙。

Formation and development process of inland river delta deposition

This paper used the flume generalized experiment to investigate the formation and development of delta deposition, after the water flow and sediment was transport into the shallow water lake from the inland river. The result showed that the delta deposition's formation and development of delta deposition can be divided into three stages on the change of plane configuration. First stage, the formation and development followed small sand wave, banded sand wave, fan delta deposition and tongue morphogenetic development, without main channel on the surface of the deposition and no string ditch on both sides. Second stage, water flow and sediment went along the surface of deposition's channel moved forward on the left and the right side region alternately. The last stage, water flow and sediment went along the new channel synchronous moved forward. In the longitudinal launching, the initial rate was larger and gradually decreasing affected by the lateral broadening. The second stage, delta deposition moved forward as relative stabilization rate alternate propulsion. The third stage, longitudinal launching rate showed a weakening trend, and finally keeped overall synchronized advance rate. In the vertical deposition, the deposition at a state rate silting up development. In the lateral broadening, water flow and sediment transverse sediment transport because of the influence of river channel mainstream swing.