基岩河道水力侵蚀模型原理及其最新研究进展

Principles of the stream power erosion model and its latest progress in research

基岩河道水力侵蚀模型是最近20年发展起来的一项地貌演化定量分析的研究方法.模型基于河流侵蚀基本物理过程、实验观测及经验公式,推导出可以应用的数学模型对河流侵蚀过程进行模拟与构造分析.目前,其主要应用在构造抬升速率研究与地貌演化模拟研究中,但由于模型在简化过程中存在一系列假设,应用中具有一定的不确定性,其中主要的不确定性来自于坡度指数、河道宽度、岩性与沉积物影响等方面,对这些关键参数与问题的定量获取研究也是目前与将来主要的研究热点.在应用基岩河道水力侵蚀模型对地貌分析中,一定要注意其限定因素与不确定因素,否则会不同程度地降低研究结果的可信性.

The stream power erosion model, which has been developed in the recent two decades, serves as a new method to quantitatively analyze the geomorphic evolution. This model is built on basic physical processes of stream erosion, practical experiments and some empirical equations, and is simplified to a mathematical model that can be easily applied in modeling and tectonic analysis. In preview studies, this model has been widely used in tectonic uplift rate study and modeling of geomorphic evolution, while great uncertainties would be introduced by some assumptions in the simplifying process. The uncertainties mainly be derived from the slop exponent, stream width, lithology and stream bed sediment. How these factors influence the model and how we can reasonably integrate them into the model are most urgent questions needing an answer. While using the stream power model in a geomorphic study, we paid great attention to those uncertainties so as to increase the reliability of our results.