Towards a uniform concept for the comparison and extrapolation of rockwall retreat and rockfall supply
Towards a uniform concept for the comparison and extrapolation of rockwall retreat and rockfall supply
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建立一个统一的概念来比较和推断岩壁退缩和落石供应
DOI：
10.1111/j.1468-0459.2007.00305.x
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
R. Dikau
中科院分区：
文献类型：
--
作者：
M. Krautblatter;R. Dikau
抽象的。在陡崖环境中，岩壁后退速率和落石供应速率是沉积物收支的基本组成部分。然而，仅使用岩性参考岩壁后退速率的标准程序与研究结果不一致，并导致超过三个数量级的变异性。本文提出的概念认为，在落石研究中固有的复杂性，可以减少，如果阶段（i）反风化，（ii）填充和消耗的中间存储在岩石面和（iii）最终落石供应到堆积体斜坡上是分开的，因为这些有不同的响应函数和控制因素。反风化响应于风化前和风化条件，而岩石面中中间储存的填充和耗尽主要是内部和外部触发的函数。通过在响应函数中加入相关控制因子，可以减小反风化速率和落石供应量中的噪声。为这三个阶段开发了简单的概念模型，并通过随时间变化的“落石输送率”联系起来，落石输送率定义为反风化和落石供应之间的差异，从而反映了岩石面中间储存的特殊重要性。现有的研究可以根据其“落石输送比”，一个类似于河流地貌学中使用的“沉积物输送比”的概念。它们的输出可以被限定为取决于（前）风化条件的触发落石供应率或反风化率。结果表明，现有的定量反风化和落石供应模型隐含地遵循所提出的概念模型，可以容纳到统一的模型。建议如何最好地将非线性，相变，路径依赖性和不同的时间尺度到落石响应函数。
Abstract. Rates of rockwall retreat and rockfall supply are fundamental components of sediment budgets in steep environments. However, the standard procedure of referencing rockwall retreat rates using only lithology is inconsistent with research findings and results in a variability that exceeds three orders of magnitude. The concept proposed in this paper argues that the complexity inherent in rockfall studies can be reduced if the stages of (i) backweathering, (ii) filling and depletion of intermediate storage on the rock face and (iii) final rockfall supply onto the talus slopes are separated as these have different response functions and controlling factors. Backweathering responds to preweathering and weathering conditions whereas the filling and depletion of intermediate storage in the rock face is mainly a function of internal and external triggers. The noise apparent in backweathering rates and rockfall supply can be reduced by integrating the relevant controlling factors in the response functions. Simple conceptual models for the three stages are developed and are linked by a time‐dependent ‘rockfall delivery rate’, which is defined as the difference between backweathering and rockfall supply, thus reflecting the specific importance of intermediate storage in the rock face. Existing studies can be characterized according to their ‘rockfall delivery ratio’, a concept similar to the ‘sediment delivery ratio’ used in fluvial geomorphology. Their outputs can be qualified as trigger‐dependent rockfall supply rates or backweathering rates dependent on (pre‐)weathering conditions. It is shown that the existing quantitative backweathering and rockfall supply models implicitly follow the proposed conceptual models and can be accommodated into the uniform model. Suggestions are made for how best to incorporate non‐linearities, phase transitions, path dependencies and different timescales into rockfall response functions.