Case Study: Equivalent Widths of the Middle Rio Grande, New Mexico
Case Study: Equivalent Widths of the Middle Rio Grande, New Mexico
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DOI：
10.1061/(asce)0733-9429(2009)135:4(306
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发表时间：
2009-04
影响因子：
2.4
通讯作者：
Claudia A. Leon;P. Julien;D. Baird
中科院分区：
文献类型：
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作者：
Claudia A. Leon;P. Julien;D. Baird
格兰德河的连续河段在很长一段时间内分别保持着50米和250米的等效河道宽度。据推测，冲积河道调整床坡度，以配合长期的变化，在渠道宽度。分析关系表明，更广泛的河流河段发展陡峭的斜坡。一个模拟方法，使用每日的水和泥沙排放模拟床高程变化的瞬态演变。的分析和数值模型是在非常好的协议与纵向剖面测量的博斯克德尔阿帕奇达到的格兰德河，NM，从1992年至1999年。50 m宽河段的坡度为50 cm/km，同一河流250 m宽河段的坡度增加到80 cm/km。这种不稳定的每日瞬态模型比较以及在恒定流量接近年平均流量的稳定瞬态解决方案。瞬态斜率调整也可以用指数模型近似。因此，格兰德河需要大约20-25年的时间才能完成其90%的坡度调整。
Successive reaches of the Rio Grande have maintained equivalent channel widths of 50 and 250 m, respectively, over long periods of time. It is hypothesized that alluvial channels adjust bed slope to match the long-term changes in channel width. Analytical relationships show that wider river reaches develop steeper slopes. A modeling approach using daily water and sediment discharges simulates the transient evolution of bed elevation changes. The analytical and numerical models are in very good agreement with the longitudinal profile measurements of the Bosque del Apache reach of the Rio Grande, NM, from 1992 to 1999. The slope of the 50 m wide reach was 50 cm/km and the slope of the 250 m wide reach of the same river increased to 80 cm/km. This unsteady daily transient model compares well with a steady transient solution at a constant discharge close to the mean annual flow. The transient slope adjustments can also be approximated with an exponential model. Accordingly, it takes about 20-25 years for the Rio Grande to achieve about 90% of its slope adjustment.