Wood dynamics in headwater streams of the Colorado Rocky Mountains
Wood dynamics in headwater streams of the Colorado Rocky Mountains
复制标题
科罗拉多落基山脉源头溪流的木材动态
DOI：
10.1029/2007wr006522
复制
发表时间：
2008
影响因子：
5.4
通讯作者：
J. Goode
中科院分区：
文献类型：
--
作者：
E. Wohl;J. Goode
1996年开始的一项为期11年的监测研究评估了科罗拉多落基山脉五条溪流的木材流动性。每个航道段长度为40-70 m。最初的调查包括通道尺寸和每一块木头的排列。每年重新调查的重点是木材的安排和持久性。平均直径为15 cm，长度为3.2 m，站点间变化不大。年平均流动率为16%至23%。平均居住时间为3.4年。木材负荷与沟宽和比降呈正相关，与相对基底淹没度和年平均洪峰流量呈负相关。生存分析表明，个别件的停留时间控制的无量纲件长度和峰值单位流功率在一年中删除。停留时间的增加，作为件长度相对于通道宽度的减少，这可以解释为一个更大的集成流场较长的作品。单个木材的流动性主要由木材特性（长度，直径，类型）控制。埋藏碎片的移动性最小。相对于其他地区的研究，停留时间的短暂可能是由于木材采伐清除了世纪前的即时和河岸木材供应后，这些通道中的木材负荷相对较低。虽然个别木材被交换，木材负荷和个别木塞的位置保持相对恒定。
An 11‐year monitoring study begun in 1996 evaluates wood mobility in five Colorado Rocky Mountain streams. Each channel reach is 40–70 m in length. Initial surveys included channel dimensions and arrangement of each piece of wood. Annual resurveys focused on wood arrangement and persistence. Average diameter of 15 cm and length of 3.2 m varied little among sites. Average yearly mobility ranged from 16% to 23%. Average residence time was 3.4 years. Wood load correlates positively with valley width and channel gradient, and negatively with relative substrate submergence and mean annual peak discharge. Survival analysis revealed that individual piece residence time was controlled by a nondimensional piece length and peak unit stream power during the year of removal. Residence time increases as piece length relative to channel width decreases, which could be explained by a greater integration of the flow field for longer pieces. Mobility of individual pieces of wood is controlled primarily by piece characteristics (length, diameter, type). Likelihood of mobility is smallest for buried pieces. The brevity of residence time relative to studies from other regions likely results from relatively low wood loads in these channels after timber harvesting cleared both instream and riparian wood supply more than a century ago. Although individual pieces of wood are exchanged, wood load and the location of individual logjams remain relatively constant.