Much of our current understanding of continental topographic evolution is rooted in measuring and predicting the rates at which rivers erode the landscape. Flume tank and field observations indicate that stochasticity and local conditions play important roles in determining rates at small scales (e.g., <10 km, thousands of years). Obversely, preserved river profiles and common shapes of rivers atop uplifting topography indicate that erosion rates are predictable at larger scales. These observations indicate that the response of rivers to forcing can be scale dependent. I demonstrate that erosional thresholds can provide an explanation for why profile evolution can be very complicated and unique at small scales yet simple and predictable at large scales.

中文翻译：

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尽管侵蚀河流景观的局部复杂性，但新兴的简单性

我们目前对大陆地形演变的大部分理解都植根于测量和预测河流侵蚀景观的速度。水槽和现场观察表明，随机性和当地条件在确定小尺度（例如，<10 公里，数千年）的速率方面起着重要作用。相反，在抬升的地形上保留的河流剖面和常见的河流形状表明，侵蚀率在更大范围内是可以预测的。这些观察结果表明河流对强迫的响应可能与尺度有关。我证明侵蚀阈值可以解释为什么剖面演化在小尺度上可能非常复杂和独特，而在大尺度上却简单且可预测。