基于元胞自动机模型的内陆河三角洲堆积体演化过程

通过建立二维元胞自动机模型,对山区河流直接进入开阔湖区后的内陆河三角洲堆积体演化过程进行研究。分析三角洲堆积体的发展过程和堆积体表面冲积河槽形态演变的规律。总结得出整体规律:先纵向推进,再垂向淤积抬升,最后横向展宽;纵向推进速率随着模拟步数的增加而减小;垂向逐渐淤积抬升;横向展宽速率随着模拟步数的增加而逐渐减小;堆积体表面的河槽形态演化分为顺直、分汊和微弯河槽3个阶段。模拟结果与已有类似物理模型试验结果基本吻合,表明元胞自动机模型可以用于模拟三角洲演化的过程。

Evolution process of delta accumulation in inland river based on cellular automata model

Through establishment of a two-dimensional cellular automata model, the evolution process of delta accumulation in inland rivers after a mountain river flows directly into open lake areas was examined. The development process of delta accumulation and the evolution laws of alluvial channel morphology on the accumulation surface were analyzed. The whole pattern was determined: first longitudinal forward, then vertical deposition uplift, and finally lateral spreading. The longitudinal forward rate decreases with the increase of the simulation steps, a gradual deposition uplift occurs in the vertical direction, and the rate of lateral spreading decreases with the increase of the simulation steps. The channel morphology evolution on the accumulation surface can be divided into three stages: the straight channel, braided channel, and micro-bend channel. The simulated results agree with existing experimental results of the physical model, indicating that the cellular automata model can be used to simulate the evolution process of the delta.