Abstract It is now widely accepted that rivers modify their erosion rates in response to variable rock uplift rates, resulting in changes in channel slope that propagate upstream through time. Therefore, present-day river morphology may contain a record of tectonic history. The simple stream power incision model can, in principle, be used to quantify past uplift rates over a variety of spatial and temporal scales. Nonetheless, the erosional model's exponents of area and slope (m and n respectively) and ‘bedrock erodibility’ (k) remain poorly constrained. In this paper, we will use a geologically and geomorphically well constrained Plio-Pleistocene volcanic landscape in central Sardinia, Italy, to calibrate the stream power erosion equation and to investigate the slip rate of faults that have been seismically quiescent in the historic past. By analysing digital elevation models, geological maps and Landsat imagery, we have identified the geomorphic expression of several volcanic features (eruption centres and basaltic lava flows) and three normal faults with 6 to 8 km fault traces within the outcrop. Downstream, river longitudinal profiles show a similar transient response to relative base level fall, probably as a result of relief inversion at the edge of the volcanic outcrop. From measurements of incision, local slope and upstream catchment area across eight different rivers, we calculate n ≈ 1, m = 0.50 ± 0.02 and, using a landscape age from literature of 2.7 Ma, bedrock erodibility k = 0.10 ± 0.04 m(1−2m) Myr−1. There are also knickpoints on rivers upstream of two normal faults, and we used numerical inverse modelling of the longitudinal profiles to predict the slip rate of these faults since 2.7 Ma. The results from the inverse model show that the erosional parameter values derived in this study can produce theoretical longitudinal profiles that closely resemble observed river profiles upstream of the faults. The lowest misfit theoretical longitudinal profiles were generated by a model of temporally discontinuous footwall uplift with consistently low throw rates (

中文翻译：

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校准河流侵蚀规律并量化河流对意大利撒丁岛断层的响应

摘要 现在人们普遍认为，河流会随着岩石抬升率的变化而改变其侵蚀率，从而导致河道坡度随时间向上游传播。因此，今天的河流形态可能包含构造历史的记录。原则上，简单的河流动力切口模型可用于量化各种空间和时间尺度上的过去抬升率。尽管如此，侵蚀模型的面积指数和坡度指数（分别为 m 和 n）以及“基岩可蚀性”（k）仍然没有受到很好的约束。在本文中，我们将使用意大利撒丁岛中部的地质和地貌约束良好的上新世-更新世火山景观来校准河流动力侵蚀方程并调查历史上地震静止的断层的滑动速率。通过分析数字高程模型、地质图和 Landsat 图像，我们确定了几个火山特征（喷发中心和玄武岩熔岩流）和露头内具有 6 至 8 公里断层痕迹的三个正断层的地貌表现。在下游，河流纵向剖面显示出对相对基准面下降的类似瞬态响应，这可能是火山露头边缘的浮雕反转的结果。通过对八条不同河流的切口、局部坡度和上游集水区的测量，我们计算出 n ≈ 1，m = 0.50 ± 0.02，并且使用文献中 2.7 Ma 的景观年龄，基岩可蚀性 k = 0.10 ± 0.04 m(1− 2m) Myr-1。两条正断层上游的河流上也有断点，我们使用纵向剖面的数值反演模型来预测自 2.7 Ma 以来这些断层的滑动率。反演模型的结果表明，本研究得出的侵蚀参数值可以产生与断层上游观察到的河流剖面非常相似的理论纵向剖面。最低失配的理论纵向剖面是由具有持续低抛率的时间不连续下盘隆起模型生成的。