The relationship between drainage density, erosion rate, and hilltop curvature: Implications for sediment transport processes CLUBB ET AL: DRAINAGE DENSITY
The relationship between drainage density, erosion rate, and hilltop curvature: Implications for sediment transport processes CLUBB ET AL: DRAINAGE DENSITY
复制标题
排水密度、侵蚀率和山顶曲率之间的关系：对沉积物输送过程的影响 CLUBB 等人：排水密度
DOI：
10.1002/2015jf003747
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Clubb F
中科院分区：
文献类型：
--
作者：
Clubb F
排水密度是描述河流网络范围的一项基本景观指标。利用渠道-坡面综合景观开发(CHILD)数值模型，比较了流域密度(DD)与侵蚀速率(E)之间的关系。我们发现，在剥离受限的河流切割模型中，改变河道坡度指数(N)控制了Ddd与E之间的关系，如果所有其他参数保持不变，则Ddw与E之间的关系将导致Ddw随E的增大。这一结果在模拟线性和非线性坡面泥沙通量时是一致的。我们还在美国五个土壤覆盖的景观中测试了D和E之间的关系：加利福尼亚州的羽毛河；加利福尼亚州的圣加布里埃尔山脉；科罗拉多州的博尔德克里克；新墨西哥州的瓜达卢佩山脉；以及华盛顿州的比特罗特国家森林。对于其中两个野外站点，我们将其与宇宙成因放射性核素(CRN)得出的侵蚀速率进行了比较，对于每个站点，我们使用平均山顶曲率作为侵蚀速率的代理，在这些站点中，CRN得出的侵蚀速率是不可用的。我们发现，除加利福尼亚州圣加布里埃尔山脉外，每个站点的Dd、E和山顶曲率之间存在显著的正相关关系。这一关系与大于1的指数一致，表明在较高的侵蚀率下，平流过程和扩散过程之间的转变发生在土壤覆盖的景观中较小的贡献区域。
Drainage density is a fundamental landscape metric describing the extent of the fluvial network. We compare the relationship between drainage density (Dd) and erosion rate (E) using the Channel‐Hillslope Integrated Landscape Development (CHILD) numerical model. We find that varying the channel slope exponent (n) in detachment‐limited fluvial incision models controls the relationship betweenDdandE, withn> 1 resulting in increasingDdwithEif all other parameters are held constant. This result is consistent when modeling both linear and nonlinear hillslope sediment flux. We also test the relationship betweenDdandEin five soil‐mantled landscapes throughout the USA: Feather River, CA; San Gabriel Mountains, CA; Boulder Creek, CO; Guadalupe Mountains, NM; and Bitterroot National Forest, ID. For two of these field sites we compareDdto cosmogenic radionuclide (CRN)‐derived erosion rates, and for each site we use mean hilltop curvature as a proxy for erosion rate where CRN‐derived erosion rates are not available. We find that there is a significant positive relationship betweenDd,E, and hilltop curvature across every site, with the exception of the San Gabriel Mountains, CA. This relationship is consistent with annexponent greater than 1, suggesting that at higher erosion rates, the transition between advective and diffusive processes occurs at smaller contributing areas in soil‐mantled landscapes.