Sediment Budgets as an Organizing Framework in Fluvial Geomorphology
Sediment Budgets as an Organizing Framework in Fluvial Geomorphology
复制标题
沉积物收支作为河流地貌学的组织框架
DOI：
10.1002/9781118648551.ch16
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发表时间：
2016
期刊：
影响因子：
4.3
通讯作者：
T. Dunne
中科院分区：
文献类型：
--
作者：
L. Reid;T. Dunne
河流地貌学涉及风化岩石碎屑的运输及其在不断演化的地貌中的堆积和组织。理论河流地貌学侧重于河流过程的机制和控制地貌演变的原理，而应用河流地貌学则致力于理解和设计与不断变化的河流系统共存的策略。每当河流地貌形态发生变化时，泥沙进出场地的运动就会出现局部不平衡。因此，对河流系统如何收集、输送和沉积沉积物的了解，对于解决集水条件变化如何影响河道、影响将持续多长时间以及反应的顺序等应用和理论问题至关重要。泥沙预算是建立这种理解的工具。泥沙收支定义了地貌演变的最基本方面：质量保护，因为它是通过在自然或人为控制施加的边界条件内作用的变形过程来实现的。关于特定河流地貌或河流系统的泥沙收支是否处于稳定状态的信息--或如果不是，则为不平衡程度--与年平均洪水、年平均径流量或河流系统的其他常用特征一样是一个基本的描述符。量化泥沙供应和输移率通常比测量水文气候量更难完成，但过去几十年的技术进步提高了确定河流系统泥沙收支的能力。即使是最基本的沉积物预算也可以防止疏忽，并指导选择进行更详细分析所需的分析工具。最终，沉淀物预算的详细程度和复杂程度受到时间和数据源和工具可用性的限制，其中许多都在本书的其他章节中进行了详细描述。本章讨论了泥沙预算的性质，提供了如何使用这些预算的例子，并描述了一种设计和编制有用预算的方法。
Fluvial geomorphology concerns the transport of weathered rock debris and its accumulation and organization into land forms that evolve continuously. Whereas theoretical fluvial geomorphology focuses on the mechanics of fluvial processes and the principles governing the evolution of landforms, applied fluvial geomorphology is devoted to understanding and designing strategies for coexisting with changing fluvial systems. Whenever a fluvial feature changes form, there is a local imbalance in the movement of sediment to and from the site. An understanding of how a river system collects, transports and deposits sediment is therefore central to addressing both applied and theoretical questions regarding how changes in catchment conditions affect channels, how long the effects will last and what the sequence of responses will be. Sediment budgets are tools for building that understanding. Sediment budgets define the most fundamental aspect of landform evolution: mass conservation as it is achieved by mor phogenetic processes acting within the boundary conditions imposed by natural or anthropogenic controls. Information about whether the sediment budget of a particular fluvial land form or a fluvial system is in a steady state — or the degree of imbalance if it is not — is as basic a descriptor as the mean annual flood, mean annual runoff or other commonly used characterizations of fluvial systems. Quantifying sediment sup plies and transport rates is typically more difficult to accomplish than measurement of hydroclimatic quantities, but technical advances during the past few decades have improved the capac ity for defining the sediment budgets of fluvial systems. Even rudimentary sediment budgets can prevent oversights and guide the selection of the analytical tools needed for more detailed analyses. Eventually, the degree of detail and sophistication of sediment budgeting is constrained by time and by the avail ability of data sources and tools, many of which are described in detail in other chapters of this book. This chapter discusses the nature of sediment budgets, provides examples of how they have been used and describes an approach for designing and constructing useful budgets.