...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth Surface Processes and Landforms: The journal of the British Geomorphological Research Group >Distribution and characterization of in-channel large wood in relation to geomorphic patterns on a low-gradient river
【24h】

Distribution and characterization of in-channel large wood in relation to geomorphic patterns on a low-gradient river

机译：低坡度河道内大型木材的分布和特征与地貌特征的关系

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A 177 river km georeferenced aerial survey of in-channel large wood (LW) on the lower Roanoke River, NC was conducted to determine LW dynamics and distributions on an eastern USA low-gradient large river. Results indicate a system with approximately 75% of the LW available for transport either as detached individual LW or as LW in log jams. There were approximately 55 individual LW per river km and another 59 pieces in log jams per river km. Individual LW is a product of bank erosion (73% is produced through erosion) and is isolated on the mid and upper banks at low flow. This LW does not appear to be important for either aquatic habitat or as a human risk. Log jams rest near or at water level making them a factor in bank complexity in an otherwise homogenous fine-grained channel. A segmentation test was performed using LW frequency by river km to detect breaks in longitudinal distribution and to define homogeneous reaches of LW frequency. Homogeneous reaches were then analyzed to determine their relationship to bank height, channel width/depth, sinuosity, and gradient. Results show that log jams are a product of LW transport and occur more frequently in areas with high snag concentrations, low to intermediate bank heights, high sinuosity, high local LW recruitment rates, and narrow channel widths. The largest concentration of log jams (21.5 log jams/km) occurs in an actively eroding reach. Log jam concentrations downstream of this reach are lower due to a loss of river competency as the channel reaches sea level and the concurrent development of unvegetated mudflats separating the active channel from the floodplain forest. Substantial LW transport occurs on this low-gradient, dam-regulated large river; this study, paired with future research on transport mechanisms should provide resource managers and policymakers with options to better manage aquatic habitat while mitigating possible negative impacts to human interests.
机译：在北卡罗来纳州罗阿诺克河下游进行了177公里的地理参考航测航道大木材（LW），以确定美国东部低坡度大河上的LW动态和分布。结果表明，系统中约有75％的LW可作为独立的LW或原木卡纸中的LW进行运输。每条河公里大约有55辆LW，每条河公里另外有59件原木堵塞。单个LW是河岸侵蚀的产物（73％是通过侵蚀产生的），并且在低流量时被隔离在中上游和上岸。该LW对于水生生境或人类风险似乎都不重要。原木堵塞在水位附近或处处于水位，使它们成为原本均匀的细颗粒通道中河岸复杂性的一个因素。使用LW频率（以千米为单位）执行分段测试，以检测纵向分布的中断并定义LW频率的均匀范围。然后分析均质河段，以确定它们与河岸高度，河道宽度/深度，弯曲度和坡度的关系。结果表明，原木堵塞是轻水运输的产物，在高钩渣浓度，低至中等河岸高度，高弯曲度，高地方轻水招募率和狭窄河道宽度的地区更常见。原木堵塞的最大浓度（21.5原木堵塞/ km）发生在主动侵蚀范围内。由于该河道到达海平面时河道能力的丧失以及无植被泥滩的同时发展，使活动河道与洪泛区森林分隔开来，该河段下游的原木堵塞浓度较低。在这条低坡度，由大坝控制的大河上发生大量的轻水运输。这项研究与对运输机制的未来研究相结合，应为资源管理者和政策制定者提供更好地管理水生生境的方案，同时减轻对人类利益的负面影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号